
Class. 



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PROLEGOMENA LOGICA. 



PROLEGOMENA LOGIC A. 



AN INQUIRY 



INTO 



THE PSYCHOLOGICAL CHARACTER 



OF 



LOGICAL PROCESSES, 



BY y 

HENRY LONGUEVILLE MANSEL, MA, 

u 

FELLOW AND TUTOR OF ST. JOHN'S COLLEGE, OXFORD. 



La Logique n'est qu'un retour de la Psychologie sur elle-meme. 

Cousin. 



OXFORD, 
WILLIAM GRAHAM: 

AND "WHITTAKER AND CO. LONDON, 

1851. 



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:, 



<fr 



y> 



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BAXTER, PRINTER, OXFORD. 



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PREFACE, 



A portion of the following pages has already- 
appeared in two Articles contributed by the Author 
to the North British Review*, The present Work 
is an attempt to exhibit more fully the relations 
there intimated as existing between Logic and 
Psychology, with some additional matters, which 
could not be included within the limits of a Review. 
The title of the work is not meant to imply that 
it contains an introduction to Logic, or is designed 
for the use of those unacquainted with its rudiments. 
On the contrary, without some previous knowledge 
of the elementary portion of that science, the 
greater part of the present Volume will not be 
intelligible. But it is intended as an inquiry into 
that which in the order of nature is prior to Logic ; 
though in the order of time it is of later scientific 
development, and in the order of study should be 
postponed till after an acquaintance at least with 
the elements of logical science : — an inquiry into 

a No. 97. Art. Philosophy of language. No. 29. Art. Recent 
extensions of Formal Logic. 

A 



11 PREFACE. 

a subject which is indicated by every page of Logic 
in which mind and its operations are mentioned, 
and which is the touchstone by which the whole 
truth and scientific value of Logic must ultimately 
be tested : — an inquiry into the constitution and 
laws of the thinking faculty, such as they are 
assumed by the Logician as the basis of his 
deductions. It is not intended as a complete 
treatise, either on Psychology alone, or on Logic 
alone ; but as an exposition of Psychology in rela- 
tion to Logic, containing such portions of the former 
as are absolutely necessary to the vindication and 
even to the understanding of the latter. 

That something of the kind is not altogether 
unneeded, will be acknowledged by those who are 
acquainted with the literature of the subject. For 
a period of seventy years, reckoning from the first 
publication of Kant's Critique of Pure Reason, 
Formal Logic, in itself and in its relations to Psy- 
chology, has been elaborated by numbers of eminent 
writers in Germany, from whose labours the English 
student has, as yet, derived hardly any benefit. 
Misconceptions are still allowed to prevail concern- 
ing the nature and office of Logic, which the 
slightest acquaintance with the actual constitution 
of human thought and its laws would suffice to 
dissipate for ever. Matters treated of by different 
logicians are alternately expelled from and restored 
to the province of the science, without the ap- 
pearance of any thing like a sound canon of criti- 






PREFACE. Ill 

cism to determine what is logical and what is not. 
Attack and defence of the study have been con- 
ducted on grounds equally untenable ; and a con- 
ception of Logic as it might be were the human 
mind constituted as it is not, is frequently tossed 
to and fro between contending parties, to the 
exclusion of Logic as it must be while the human 
mind is constituted as it is. 

In relation to the studies of this University, it is 
equally necessary to revise and fix exactly our 
conception of Logical Science, amid the conflicting 
theories of ancient and modern philosophy. We 
have recently passed a Statute, enacting, with regard 
to two successive Examinations, that a proficiency 
in Logic is to have considerable weight in the 
distribution of honours. But the present state of 
logical literature is not such that the mere mention 
of the subject is sufficient. To say that by Logic 
is meant what Logic always has meant in the 
University Statutes, is simply to say that we inten- 
tionally ignore all that has been done in modern 
times for the improvement of the science. To say 
that we mean Logic in its present acceptation, 
is to open the floodgates to a host of incon- 
gruous and bewildering systems, having nothing 
in common but the name. To leave the matter 
to right itself by tradition or custom, is only to 
correct the deficiencies of our theory by the 
laxity of our practice. What Logic does our 
new Statute recommend ? Is it Aristotle ? is it 

a2 



IV PREFACE. 

the Schoolmen? is it Bacon? is it Aldrich ? is it 
Archbishop Whately ? is it Mr. Mill ? is it Mr. De 
Morgan? is it Wolf? is it Kant? is it Hegel? 
Most of these already exercise some indirect in- 
fluence on our studies and examinations ; and it is 
merely the want of good translations that saves us 
from being overwhelmed by an additional mass of 
incongruities from Germany. 

To remedy these evils, present and prospective, 
there is but one course open to us; — an acknow- 
ledged and systematic teaching of Logic from some 
one definite point of view. The spirit of logical 
study in this University, after remaining for a con- 
siderable time almost in a dormant state, was revived 
some years back by the publication of Archbishop 
Whately's Elements, and, ever since that period, 
has been prosecuted with a good deal of irregular 
energy. But, though a considerable amount of 
valuable material has thus been incorporated with 
the studies of the University, we can hardly be 
said to have a system ; and, without a system, the 
student of Logic will gain little more advantage 
from the heterogeneous reading of the present 
generation than from the stagnation of the last. 

Few who are acquainted with the various logical 
systems of modern times will hesitate to give a 
decided preference over all others to the formal 
view of the science, which from the days of 
Kant has gradually been advancing to perfection. 
Whether we regard the unity and scientific com- 



PREFACE. V 

pleteness of the system itself, the great names by 
which it is supported, the valuable works that 
might easily be made available for its communica- 
tion, or the facility with which it might be in- 
troduced into the existing course of study, in all it 
possesses unquestionable advantages, as the basis 
of logical instruction. But, on the other hand, its 
compass is small, and its contents, though clear 
and definite, are, taken by themselves, too meagre 
to be an adequate substitute for the miscellaneous 
reading which is at present misnamed Logical. To 
supply this defect, tw 7 o courses are open. The 
study of Formal Logic may be combined either 
with its objective or with its subjective applications. 
We may treat, that is to say, a system of Logic, 
either in connection with some of the various objects 
of thought to which it may in practice be applied, 
or in relation to the thinking mind and to that 
mental philosophy of which it forms a portion. 
The former method has been abundantly tried, and 
has abundantly failed in the trial. A system of 
Logic treated in its objective application has no 
alternative between an impossible universality or 
an arbitrary exclusiveness. By whatever right 
one iota of the matter of thought can claim ad- 
mission into the system, by the same right the 
whole universe of human knowledge is entitled to 
follow. Such a method can only be employed as 
a bad means of collecting desultory information on 



VI PREFACE. 

» 

unconnected subjects. As a system, it postulates 
its own failure. 

It is in connection, not in confusion, with 
cognate sciences, as a branch of mental philosophy, 
that Logic may and ought to be studied. One of 
the objects of the present work is to shew that 
Logic as a science cannot be rightly understood 
and appreciated, except in relation to Psychology. 
The neglect of this relation has been acknowledged 
as the weak side of the Kantian philosophy b : its 
recognition has been imperatively demanded by 
the ablest modern writers on the subject. " Selon 
moi," says M. Duval- Jouve, " l'objet de la logique 
n'est pas seulement la direction de l'intelligence, 
mais encore V etude de l'intelligence ; la direction 
apres l'etude ; et un traite de logique doit com- 
prendre la description du fait intellectuel, la 
theorie de ses lois, l'expose des regies qu'il doit 
reconnaitre, soit dans son etat psychologique et de 
pure pensee, soit dans sa manifestation par la 
parole c ." The propriety of including these psy- 
chological matters in a Treatise on Logic may be 
questioned ; but to the necessity of including them 
in a philosophical course, of which Logic should 
form a portion, the whole history of the science 
bears witness. The alliance established of old 
between Logic and Metaphysics was dissolved by 

b See Fries, System der Logik, p. 22. 
c Traite de Logique, Preface, p. viii. 



PREFACE. Vll 

the Critical Philosophy of Kant, and cannot be 
restored, except by identifying the two, with Hegel. 
To those who reject this alternative, a blank is 
made in philosophical study, which can only be 
adequately supplied by a well-connected course of 
Mental Science, embracing, as its constituent por- 
tions, the three cognate subjects of Logic, Ethics, 
and Psychology. 

To Ethics, as well as to Logic, Psychology is an 
indispensable supplement. The science of man as 
he ought to be must be based on that of man as 
he is. In Moral Philosophy, as in Logic, questions 
of a psychological character meet us at every stage 
of our course ; and the value of every ethical 
system must ultimately be tested on psychological 
grounds. Perhaps it is not too much to say, 
that half the ethical systems which have been at 
different times in vogue, have started from a psy- 
chological assumption, which, consistently carried 
out, would make Ethical Philosophy impossible. 

May it be allowed to suggest a still higher 
application of the same criterion ? In the very 
conception of Revealed Religion, as a commu- 
nication from an Infinite to a finite Intelli- 
gence, is implied the existence of certain ideas of 
a purely negative character, the purpose of which 
is not speculative but regulative truth ; which are 
designed, not to satisfy our reason, but to guide our 
practice. These, from their very nature, are beyond 
the criticism of reason. But in order to discri- 



Vlll PREFACE. 

minate accurately between the provinces of reason 
and faith, to determine what we may and what we 
may not seek to comprehend as a speculative 
truth, an examination of the limits of man's mental 
powers is indispensable. The ground of many a 
controversy might be considerably narrowed, were 
we to inquire at the outset what are the mental 
powers that can be brought to the solution of the 
question, and how are they related to the data on 
which they must operate. Fichte made his earliest 
attempt, as a disciple of the Kantian philosophy, 
by an Essay towards a Critique of every Revelation. 
The positive portion of his principles of criticism 
(for many of them have a negative character only) 
might be better applied to a Critique of every 
Critique of Revelation : — an inquiry, that is to 
say, what portion of the contents of Revelation, 
as addressed to human minds, can be wrought by 
human interpretation into the form of speculative 
dogmas. 

" La psychologie," says M. Cousin, " n'est as- 
surement pas toute la philosophic, mais elle en est 
le fondement." If there be any truth in this saying 
of one of the highest philosophical authorities of 
our own or of any age, it will follow of necessity 
that a course of instruction in this fundamental 
branch must be an integral and indispensable 
portion of any system of philosophical teaching. 

The above remarks are designed to apply only 
to Logic in its proper place, at the end of the 



PREFACE. IX 

academical course, in conjunction with cognate 
portions of philosophy. The anomalous position 
assigned to Logic in the honours of the middle 
examination seems to have got into the Statute 
by an oversight, and will doubtless be repealed 
after a little experience of its excessive practical 
inconvenience to teacher, learner, and examiner. 
Logic, like Justice, has three stages, but in the 
inverse order. 

to?s /ieV iv (pdei, 
ra &' iv fxeraixH'^ o'K-otov 
fievei xpovi£ovTa (3pvei, 
tovs §' ciKpavros e^ei vv£. 

A dim religious twilight broods over the middle 
period of the young logician's course, when thought 
is just beginning to break through the thick dark- 
ness of definitions and mnemonics learnt by rote, 
and Barbara Celarent is invested with somewhat 
of the sacredness and mystery of Koyij ofiTra^. 
It is an interesting state of mind, and will ripen 
well when it has done fermenting ; but it should 
not be too early disturbed by the rude touch of an 
Examiner. We did well to get rid of the darkness 
when we abolished the Logic of Responsions. 
May the twilight of the middle period share the 
same fate as speedily as possible ! 

The psychological criticisms of the present work 
are mainly limited to logical questions, and are 
designed to throw some light on matters which, 
almost from the commencement of my logical 



X PREFACE. 

studies, have appeared to me to stand in especial 
need of elucidation. Much of what has been 
acquired from foreign sources, with much labour 
and little guidance in the search, might have been 
learned in an easier and more direct manner, had 
the course which I have ventured to recommend 
been adopted in relation to my own early studies. 
The numerous obligations which the work is under 
to previous writers are most of them acknow- 
ledged as they occur. One or two, however, 
demand an express mention here. The reader 
who is familiar with Kant's writings will probably 
discern obligations to the Critical Philosophy in 
almost every page ; even where the language of 
Kant has been departed from, and the difference 
in detail is such as would not justify a direct refer- 
ence to his works. The method and material for 
thinking derived from the study of the Kantian 
philosophy is in many respects far more valuable 
than the direct information communicated. This 
is especially the case with a student who views 
that philosophy from the psychological rather 
than the metaphysical side, in its relation to 
Hume and Locke rather than to Wolf and Leib- 
nitz, and who endeavours to combine the materials 
thence obtained with the most valuable results of 
the Scottish philosophy, which owes its rise, like 
the Kantian, to the scepticism of Hume. 

To two eminent living authors a similar ac- 
knowledgment is due. The German side of 



PREFACE. XI 

M. Cousin's Eclecticism approaches, in aim at 
least, if not in method, nearer to the philosophy 
of Schelling and Hegel, than to that of Kant. 
It is natural, therefore, that his view of the limits 
of human thought, and consequently of the pro- 
vince of Logic and of its relation to Psychology, 
should contain much which cannot be directly 
transferred to the pages of a work which advocates 
a strictly formal view of Logic, and which would 
rather contract than enlarge the limits assigned by 
Kant to the Understanding and the Reason. But 
the writings of M. Cousin are indispensable to all 
who would gain a true estimate of the importance 
of Psychology and its position in a philosophical 
course ; and the benefits which I am conscious of 
having derived from their study are far more than 
can be adequately expressed by a direct acknow- 
ledgment of passages borrowed from them. From 
the author's view of the office of Logic I have 
departed widely ; which makes it the more neces- 
sary to confess the numberless advantages derived 
from his writings, in relation to almost every point 
treated of in the following pages. 

In many points in which I have departed from 
the doctrines of the great Eclectic, I am much 
indebted to the writings of his illustrious critic, 
Sir William Hamilton. The same acknowledg- 
ment may indeed be made in relation to nearly 
the whole contents of the present volume, partly 
by way of direct obligation, and still more by way 



Xll PREFACE. 



of hints and suggestions of questions to be solved 
and the method of their solution. I cannot indeed 
claim the sanction of this eminent authority for 
any statement which is here advanced, except 
where direct reference is made to his writings ; 
yet probably, even where I have differed from 
him in opinion, there is much that would never 
have been written at all, but for the valuable aid 
furnished by him. To say that I have occasionally 
ventured to dissent from the positions of each and 
all of the philosophers to whom I am so much 
indebted, is only to say that I have endeavoured 
to study their works in the spirit in which they 
themselves would wish to be studied ; with the 
respect and gratitude of a disciple, but, it is hoped, 
without the servility of a copyist. 

For the phraseology which I have occasionally 
been compelled to employ in the course of the 
following remarks, no apology will be required 
by those acquainted with the history of mental 
science. In no branch of study is it so necessary 
to observe the Aristotelian precept, bvoixaroiToieiv 
o-a(j)r)i>€ia? eveitev. Nine tenths of the confusion 
and controversy that have existed in this depart- 
ment are owing to that unwillingness to innovate 
in matters of language, which leads to the employ- 
ment of the same term in various shades of 
meaning and with reference to various phenomena 
of consciousness. In this respect, philosophy is 
under deep obligations to the purism of German 



PREFACE. Xlll 

writers, which has enabled subsequent thinkers to 
examine the most important problems of Psycho- 
logy apart from the old associations of language. 
A new phraseology may occasion some little dif- 
ficulty at the outset of a work ; but to adhere to 
an inadequate vocabulary, merely because its ex- 
pressions are established, is to involve the whole 
of the subject in hopeless confusion and obscurity. 
In this respect, however, I trust I shall not be 
found to have departed from authorized language 
in a greater degree than is absolutely necessary 
for the purpose of communicating to English 
readers some of the most valuable results of 
German thought, and of carrying into effect the 
main design of the present Essay, — that of testing 
the received processes of Logic, by reference to 
the facts of human consciousness. 



CONTENTS. 



Page 

Chap. I. On Thought, as distinguished from other 

facts of Consciousness. .... 1 

Chap. II. On the three Operations of Thought. . 49 

Chap. III. On Law, as related to Thought and other 

objects. 70 

Chap. IV. On the Psychological character of Mathe- 
matical Necessity. 90 

Chap. V. On the Psychological character of Meta- 
physical Necessity. . . . . . 117 

Chap. VI. On Logical Necessity and the Laws of 

Thought. ....... 167 

Chap. VII. On the Matter and Form of Thought. 226 

Chap. VIII. On Positive and Negative Thought. . 246 

Chap. IX. On Logic, as related to other Mental 

Sciences 259 

Appendix. 289 



PROLEGOMENA LOGIC A. 



CHAP. I. 

ON THOUGHT, AS DISTINGUISHED FEOM OTHER FACTS OF 
CONSCIOUSNESS. 

Without entering into the countless disputes 
which have taken place concerning the nature and 
definition of Logic a , it is sufficient to observe that 
it will be treated in the following pages, in accord- 
ance principally with the views of Kant, as the 
Science of the Laws of Formal Thinking. In the 
wide sense, indeed, in which the term is used by 
Archbishop Whately, it may be admitted that 
Logic, as furnishing rules to secure the mind from 
error in its deductions, is also an Art, or, to speak 
more correctly, a Practical Science \ Still, it may 

a For a summary of various opinions on this question, see 
Zabarella de Natura Logics, lib. i. Smiglecii Logica. Disp. ii. 
Qu. v. and Sir W. Hamilton, Edinburgh Revieiv, No. 115, 
p. 203. 

b For the distinction between these terms, see Wolf, Phil. 
Rat. Proleg. §. 10. " Omnis Logica utens est habitus, qui 
proprio exercitio comparatur, minime autem discendo acqui- 
ritur, adeoque et ipsa doceri nequit. Quamobrem, cum 
Logica omnis vel sit docens vel utens, neque enim prseter 



2 PROLEGOMENA LOGICA. 

be questioned whether the practical service thus 
performed by Logic can with propriety be allowed 
to influence its definition. The benefits performed 
by Logic as a medicine of the mind, however highly 
we may be disposed to rate them, are accidental 
only, and arise from causes external to the Science 
itself: its speculative character, as an inquiry into 
the laws of thought, is internal and essential. To 
the twofold character of Logic two conditions are 
necessary. Firstly, that there exist certain mental 
laws to which every sound thinker is bound to 
conform. Secondly, that it is possible to trans- 
gress those laws, or to think unsoundly. On the 
former of these conditions depends the possi- 
bility of Logic as a speculative Science: on the 
latter, its possibility as a practical Science or Art. 
Now, if we look at these two conditions with refer- 
ence to the actual contents of pure Logic, it is 
manifest that the abrogation of the first would 
utterly annihilate the whole Science ; whereas the 
abrogation of the second would at most only neces- 
sitate the removal of a few excrescences, leaving 
the main body of Logical doctrine substantially as 
it is at present. Suppose, for example, that the 
difference between sound and unsound reasoning 

regularum notitiam atque habitum eas ad praxin transferendi 
tertium concipi potest ; sola Logica artificialis docens ea est, 
quae doceri adeoque in numerum disciplinarum philosophica- 
rum referri potest. Atque ideo quoque Logicam definivimus 
per scientiam, minime autem per artem vel habitum in genere, 
quod genus convenit Logica utenti." 



PROLEGOMENA LOGICA. d 

could be discerned in individual cases as a matter 
of fact, but that we had no power of classifying 
the several instances of each and referring them 
to certain common principles. It is clear that, 
under such a supposition, the present contents of 
Logic, speculative and practical, could have no 
existence. The number of sound and unsound 
thinkers in the world might remain much as it is 
now, but the impossibility of investigating the prin- 
ciples of the one and applying them to the correc- 
tion of the other would make an Art or Science 
of Logic unattainable. But let us imagine, on the 
other hand, a race of intelligent beings, subject to 
the same laws of thought as mankind, but inca- 
pable of transgressing them in practice. The 
elements of existing Logic, the Concept, the Judg- 
ment, the Syllogism, would remain unaltered. The 
Science of Logic would investigate the laws of 
unerring Reason, as the Science of Astronomy 
investigates the unvarying laws of the heavenly 
phenomena ; but an Art of Logic, to preserve the 
mind from error, would be as absurd as an Art of 
Astronomy proposing to control and regulate the 
planets in their courses. From these consider- 
ations it follows that, even granting Logic to be, 
under existing circumstances, both Science and 
Art, yet the former is an essential, the latter an 
accidental feature; the one is necessarily inter- 
woven with the elements of the system, the other 
a contingent result of the infirmities of those who 

b2 



3 PROLEGOMENA LOGICA. 

possess it. In this respect, pure Logic may not 
unfairly be compared to Mechanics treated as a 
branch of Mathematics. As Sciences, both proceed 
deductively from assumptions more or less incon- 
sistent with the actual state of things. As Arts, 
neither can be put in practice without making 
allowance for contingencies neglected in the scien- 
tific theory. The assumed logical perfection of 
thought bears about the same relation to the 
ordinary state of the human mind as the assump- 
tion of perfectly rigid levers and perfectly flexible 
cords bears to the actual condition of those instru- 
ments in practice. But, on the other hand, the 
possibility of making such allowances implies that 
the difference between practice and theory is one 
of degree only, and not of kind. The instrument 
as used may not be identical with the instrument 
as contemplated, but it must be supposed capable 
of approximation to it. A Science of the Laws of 
Thought is only valuable in so far as its laws are 
acknowledged to be those to which actual thinking 
ought, as far as possible, to conform, and which, 
if fully complied with, would represent only the 
better performance of existing obligations, not the 
imposition of new ones. The same may be said 
of Ethical Philosophy likewise. In describing the 
perfection of moral and intellectual virtue, we 
describe a standard to which, in the existing state 
of human nature, no man does or can attain ; but 
the whole value of the portrait is derived from its 



PROLEGOMENA LOGICA. 5 

being a more or less accurate representation of man 
as he ought to be, not the imaginary sketch of a 
being of a totally distinct kind . 

In order therefore to the right appreciation of 
any given system of Logic, it becomes necessary to 
ask, what is the actual nature of Thought as an 
operation, to what laws is it subject, and to what 
extent are they efficient ? This inquiry does not, 
strictly speaking, fall within the province of Logic 
itself. No Science is competent to criticise its 
own principles. That there is such an operation 
as thinking and certain laws to which it is bound 
to conform, the Logician does not question, but 
assumes. Whether there are other mental ope- 
rations besides thinking, and whether these must 
act in combination with Thought for the attain- 
ment of any special class of truths ; these and 
such like questions it is beyond his province to 
investigate. His own branch of inquiry is twofold, 
partly constructive, and partly critical. In the 
former capacity, he inquires, what are the several 
forms, legitimate or illegitimate, which Thought as 
a product will assume, according as the act of 
thinking is or is not conducted in conformity to 



c " Beide, Logik und Ethik, haben Vorschriften aufzusteilen, 
nack welchen sick, kier das Denken, dort das Handeln rickten 
soil, okgleick es sick eins wie das andere, aus psychologiscken 
Griinden gar oft in der Wirklickkeit nickt darnack ricktet, 
und nickt darnack rickten kann." Herbart. Psychologie als 
Wissenschaft, Tb. ii. §.119. 



O PROLEGOMENA LOGICA. 

its given laws. In the latter capacity, he sifts 
and examines the special products of this or that 
thinker, and pronounces them, according to the 
features which they exhibit, to be legitimately 
produced or otherwise d . 

Beyond the boundaries of pure Logic there is 
thus another and an important field of inquiry. Is 
the mind capable of other operations besides those 
of Thought, arid are there other kinds of mental 
rectitude besides that which results from the con- 
formity of Thought to its own laws ? Do the 
several mental faculties act in the pursuit of truth 
conjointly or separately ? Does each process 
guarantee the complete attainment of a limited 
class of truths, or the attainment of a single 
element which becomes truth only in combina- 
tion ? Do the Laws of Thought, as assumed by 
Logic, exhibit those features which, from the 
general constitution of the human mind and the 
peculiar character of the thinking faculty, they 
might be expected to exhibit? In relation to 
these and similar questions, Logic is subordinate 
to Psychology. 

To Psychology we must look for the explanation 
and justification of the peculiar features of Logic. 
Logic, says one antagonist, furnishes no criterion 
of material truth and falsehood. It may be that, 
from the constitution of the human mind, such a 

d See Drobisch, Neue Darstellung der Logik, §. 9. Fries 
em der Logik, §. 1. 



PROLEGOMENA LOGICA. 7 

criterion is impossible. Its principles, says another, 
are mere frivolous tautologies. It may be that 
this very tautology has a psychological significance, 
that it is the necessary consequence of a mind 
gazing upon its own laws. It is barren in the 
production of positive science. It may be that 
thought alone was never designed by man's Maker 
to be otherwise. As an instrument, it has at- 
tempted much and accomplished little. The fault 
may lie, not in the tool, but in the workman. 
Before we condemn Logic for what it does not 
perform, or despise it for what it does, it may be 
as w T ell to ask, what we may learn elsewhere of the 
nature of the thinking faculty, and what it may 
reasonably be expected to accomplish. 

In order, therefore, to determine accurately 
the province and capabilities of Logic, it will be 
necessary to examine the psychological distinction 
between Thought, properly so called, and other 
phenomena of mind. This being ascertained, there 
will remain the inquiry, in what manner our con- 
sciousness itself and the several objects submitted 
to it may be regarded as subject to law, what 
are the different classes of laws, whether of the 
subject or of the object, the characteristic features 
of each, their mode of determining the several 
operations subject to them, and the consequent 
character of the respective products. 

Every state of consciousness necessarily implies 
two elements at least ; a conscious subject, and an 






8 PROLEGOMENA LOGICA. 

object of which he is conscious. In every exercise, 
for example, of the senses, we may distinguish the 
object seen, heard, smelt, touched, tasted, from 
the subject, seeing, hearing, smelling, touching, 
tasting. In every emotion of pleasure or of pain, 
there is a certain affection, agreeable or dis- 
agreeable, existing within me, and of this affection 
I am conscious. In every act of volition, there 
takes place a certain exercise of my will, and I am 
conscious that it takes place. In this point of 
view, it is not necessary to enter on the often 
disputed question, whether such states of conscious- 
ness furnish immediate evidence of the existence 
of a world external to ourselves. That of which 
I am directly conscious may be an object nu- 
merically distinct from myself, or it may be a 
modification of my own mind. All that need be 
insisted upon here is, that there is present an 
individual object, whether thing, act, or state of 
mind, and that we are conscious of such an object 
as existing within or without ourselves. A psycho- 
logical dualism is implied in the very notion of 
consciousness : whether this necessarily involves an 
ontological dualism, it is beyond our present purpose 
to inquire 6 . 

e This point has been already argued fully and satisfactorily 
by the great modern advocate of Natural Dualism, Sir William 
Hamilton. The reader is referred to his edition of Eeid's 
works, especially to his notes B and C, for a masterly dis- 
sertation on this important question. 



PROLEGOMENA LOGICA. V 

But to constitute an act of Thought, more is 
required than the immediate relation of subject to 
object in consciousness. Every one of the above 
states might exist in a mind totally incapable of 
thought. Let us suppose, for example, a being, 
in whose mind every successive state of conscious- 
ness was forgotten as soon as it had taken place. 
Every individual object might be presented to 
him precisely as it is to us. Animals, men, trees, 
and stones, might be successively placed before 
his eyes ; pleasure, and pain, and anger, and fear, 
might alternate within him ; but, as each departed, 
he would retain no knowledge that it had ever 
existed, and consequently no power of comparison 
with similar or dissimilar objects of an earlier or 
later consciousness. He would have no know- 
ledge of such objects as referred to separate notions ; 
he could not say, this which I see is a man, or a 
horse ; this which I feel is fear, or anger. He 
would be deficient in the distinctive feature of 
Thought, the concept or general notion resulting 
from the comparison of objects. Hence arises 
the important distinction between Intuitions*, in 
which the object is immediately related to the 

f Here, and throughout the following pages, the word 
Intuition is used in the extent of the German Anschauung, to 
include all the products of the perceptive (external or internal) 
and imaginative faculties ; every act of consciousness, in short, 
of which the immediate object is an individual, thing, state, or 
act of mind, presented under the condition of distinct exist- 
ence in space or time. 



10 PROLEGOMENA LOGICA. 

conscious mind, and Thoughts, in which the 
object is mediately related through a concept 8 
gained by comparison. The former contains 
two elements only, the subject and the object 
standing in present relation to each other. The 
latter contains three elements, the thinking sub- 
ject, the object about which he thinks, and the 
concept mediating between the two h . Thus even 
the exercise of the senses upon present objects, in 
the manner in which it is ordinarily performed by 
a man of mature faculties, does not consist of 
mere intuition, but is accompanied by an act of 
thought. In mere intuition, all that is simul- 
taneously presented to the sense appears as one 
whole ; but mere intuition does not distinguish 

« The revival of this term, unfortunately, till very recently, 
suffered to grow obsolete in philosophy, will need no apology 
with those who are acquainted with the writings of Sir W. 
Hamilton. It is absolutely necessary to distinguish in lan- 
guage between the act of thought and its object, a distinction 
expressed in Greek by vorja-ts and uorjfia, and in the following 
remarks by conception and concept. The latter term has been 
fully sanctioned by the usage of French philosophers, as well 
as of the eminent writer above mentioned. 

h " In apprehending an individual thing, either itself through 
sense or its representation in the phantasy, we have, in a 
certain sort, an absolute or irrespective cognition, which is 
justly denominated immediate, by contrast to the more relative 
and mediate knowledge which, subsequently, we compass of 
the same object, when, by a comparative act of the under- 
standing, we refer it to a class, that is, think or recognise it, 
by relation to other things, under a certain notion or general 
term." Sir W. Hamilton, Reid's Works, p. 804. 



PROLEGOMENA LOGICA. 1 1 

its several parts from each other under this or 
that notion. I may see at once, in a single pano- 
rama, a ship upon the sea, an island lying behind 
it, and the sky above it. To mere intuition this 
is presented only in confusion, as a single object. 
To distinguish its constituent portions, as sea and 
land, ship and sky, requires a comparison and 
classification of them relatively to so many separate 
concepts existing in the mind; and such classi- 
fication is an act of Thought \ 

In every act of Consciousness the ultimate 
object is an individual. But in intuition this 
object is presented to the mind directly, and does 
not imply the existence, past or present, of any 
thing but itself and the mind to which it is pre- 
sented. In thought, on the other hand, the indi- 
vidual is represented by means of a concept, which 
contains certain attributes applicable to other indi- 
viduals of the same kind. This implies that there 
have been presented to the mind prior objects of 
intuition, originating the concept or general notion 
to which subsequent objects are referred. . Hence 
arises another important distinction. All intuition 
is direct and presentative ; all thought is indirect 
and representative. 

This distinction necessitates a further remark 
on the characteristic feature of thought, as com- 
pared with one special class of intuitions. That 
sensitive perception takes place through the me- 

1 Hoffbauer, Logik, §.10. 



12 PROLEGOMENA LOGICA. 

dium of a representative idea, is a hypothesis 
which was made more than questionable by the 
philosophy of Reid, and may be regarded as com- 
pletely overthrown by the recent labours of his 
illustrious editor, Sir William Hamilton. But 
there still remains the faculty of Imagination, 
whose office is the production of images repre- 
sentative of the several phenomena of Perception k , 

k The term Perception requires a few words in explanation. 
In modern philosophy, from Descartes to Keid, this term 
was used widely, as coextensive with Apprehension or Con- 
sciousness in general, with some minor modifications, for an 
account of which the reader is referred to Sir W. Hamilton's 
Eeid, p. 876. By Eeid and his followers it was used for 
the consciousness of an external object presented to the 
mind through the organs of sense, as distinguished from 
Sensation, the consciousness of an affection of the subject 
through the same organs. In this sense they are clearly 
distinguished by M. Eoyer Collard, Jouffroy's Eeid, hi. p. 329. 
" II y a dans l'operation du toucher sensation et perception 
tout ensemble : changement d'etat ou modification interieure, 
c'est la sensation ; connaissance d'un objet exterieur, c'est la 
perception." Cf. Eeid, Intell. Powers, Essay i. ch. i. Stewart, 
Outlines of Moral Philosophy, §.15. According to M. Eoyer 
Collard, the senses of smell, hearing, and taste, give rise to 
sensations only ; touch is in every case an union of sensation 
and perception ; while sight holds an intermediate and doubtful 
position, as informing us of the existence of extension, but 
only in two dimensions of space. Sir W. Hamilton, on the 
other hand, holds that the general consciousness of the 
locality of a sensorial affection ought to be regarded as a 
Perception proper ; and, in accordance with this view, he has 
announced the important law, that Sensation and Perception, 
though always coexistent, are, as regards their intensity, 
always in an inverse ratio to each other. Some recent French 



PROLEGOMENA LOGICA. 13 

internal as well as external. In relation to this 
faculty, the criterion above given as characteristic 
of Thought requires a few words of explanation. 

Imagination, regarded as a product, may be 
defined, the consciousness of an image in the 
mind resembling and representing an object of 
intuition 1 . It is thus at the same time presentative 

philosophers, influenced by the union of physiological with 
psychological researches, have employed the term Perception 
in another sense, to denote Sensation with Consciousness, 
Sensation being extended to those affections of the nervous 
organism of which we are not conscious. This occurs in the 
writings of Maine de Biran, and appears to have misled 
M. Kavaisson into imagining that that philosopher had anti- 
cipated the above-mentioned law of Sir W. Hamilton. The 
passage alluded to is apparently one in the Essai sur la de- 
composition de la Pensee, p. LI 6. but the resemblance is 
merely verbal. 

In the text, Perception is employed to denote all those 
states of Consciousness which are presentative only, not 
representative. It will thus include all intuitions except 
those of Imagination, and may be divided into external or 
sensitive, and internal; the former corresponding to the Per- 
ception of Eeid. This use of the term, allowance being made 
for a different theory of external Perception, accords with 
that of Kant. 

1 This is the ordinary psychological sense of Imagination ; 
however variously the term may have been employed in 
reference to poetry, and generally to the philosophy of taste. 
It corresponds with the definition given by Descartes, " ima- 
ginari nihil aliucl est quam rei corporece Jiguram seu imaginem 
contemplari ;" except that the latter is incorrectly limited to the 
reproduction of objects of sight only. The beautiful lines of 
Shelley furnish an exact description of imagination relatively 
to two other senses : 



14 PROLEGOMENA LOGICA. 

and representative. It is presentative of the image, 
which has its own distinct existence in conscious- 
ness, irrespective of its relation to the object which 
it is supposed to represent. It is representative of 
the object which that image resembles; and such 
resemblance is only possible on the condition that 
the image be, like the object, individual. If we 
try to form in our minds the image of a triangle, 
it must be of some individual figure, equilateral, 
isosceles, or scalene. It is impossible that it should 
be at the same time all of these, or none. It may 
bear more or less resemblance to the object which 
it represents ; but it can attain resemblance at all 
only by being, like the object itself, individual. 
I may recall to mind, with more or less vividness, 
the features of an absent friend, as I may paint 
his portrait with more or less accuracy ; but the 
likeness in neither case ceases to be the individual 
representation of an individual man. But my 
notion of Man in general can attain universality 
only by surrendering resemblance. It becomes 

" Music, when soft voices die, 

Vibrates in the memory; 

Odours, when sweet violets sicken, 

Live within the sense they quicken." 
But the operation of the imaginative faculty must not be 
confined even to the general field of sensations. The im- 
portant question, How many presentative faculties has man? 
will be referred to again. The province of imagination will 
be determined by the answer to this question, as every 
original presentation may be represented in a phantasm. 



PROLEGOMENA LOGICA. 15 

the indifferent representative of all mankind only 
in so far as it has no special likeness to any 
one. It is thus not the adequate and actual 
representative of any single object, but an in- 
adequate and potential representative of many : 
that is, it may in different acts of thought be 
employed in relation to distinct, and in some 
respects dissimilar, individuals of the same class. 
From this neglect of individual characteristics 
arises the first distinguishing feature of a concept ; 
viz. that it cannot in itself be depicted to sense or 
imagination™. It is not the sensible image of 
one object, but an intelligible relation between 
many. 

A second important characteristic of all con- 
cepts is, that they require to be fixed in a repre- 
sentative sign. This characteristic cannot indeed be 
determined a priori, from the mere notion of the 
concept as universal, but it may be proved to a 
moral certainty a posteriori, by the inability of 
which in practice every man is conscious, of ad- 
vancing, without the aid of symbols, beyond the 
individual objects of sense or imagination. In the 
presence of several individuals of the same species, 
the eye may observe points of similarity between 
them; and in this no symbol is needed ; but every 
feature thus observed is the distinct attribute of a 
distinct individual, and, however similar, cannot be 
regarded as identical. For example: I see lying 

m Cf. Hamilton on Keid, p. 360, 



16 PROLEGOMENA LOGICA. 

on the table before me a number of shillings of 
the same coinage. Examined severally, the image 
and superscription of each is undistinguishable from 
that of its fellow ; but, in viewing them side by- 
side, space is a necessary condition of my percep- 
tion ; and the difference of locality is sufficient to 
make them distinct, though similar, individuals n . 
The same is the case with any representative 
image, whether in a mirror, in a painting, or in the 
imagination, waking or dreaming. It can only be 
depicted as occupying a certain place ; and thus 
as an individual and the representative of an indi- 
vidual. It is true that I cannot say that it repre- 
sents this particular coin rather than that ; and 
consequently it may be considered as the repre- 
sentative of all, successively but not simultaneously. 
To find a representative which shall embrace all 
at once, I must divest it of the condition of occu- 
pying space ; and this, experience assures us, can 
only be done by means of symbols, verbal or other, 
by which the concept is fixed in the understand- 
ing. Such, for example, is a verbal description of 
the coin in question, which contains a collection 
of attributes freed from the condition of locality, 
and hence from all resemblance to an object of 
sense. If we substitute Time for Space, the same 
remarks will be equally applicable to the objects of 

n On this ground Kant refutes Leibnitz's principle of the 
identity of indiscernibles, a principle applicable to concepts, but 
not to objects of intuition. 



PROLEGOMENA LOGICA. 17 

our internal consciousness. Every appetite and 
desire, every affection and volition, as presented, 
is an individual state of consciousness, distinguished 
from every other by its relation to a different 
period of time. States in other respects exactly 
similar may succeed one another at regular inter- 
vals; but the hunger which I feel to-day is an 
individual feeling, as numerically distinct from that 
which I felt yesterday or that which I shall feel 
to-morrow, as a shilling lying in my pocket is from 
a similar shilling lying at the bank. Whereas my 
notion of hunger, or fear, or volition, is a general 
concept, having no relation to one period of time 
rather than to another, and, as such, requires, like 
other concepts, a representative sign. 

Language, taking the word in its widest sense, 
is thus indispensable, not merely to the commu- 
nication, but to the formation of Thought. This 
doctrine is not unfrequently estimated as the cor- 
relative or consequent of that which derives all 
knowledge from sensation ; an estimate apparently 
warranted by the association of the two theories 
in the philosophy of Condillac. But it would not 
be difficult to shew that the ultra-sensational 
philosophy is that which could most easily dis- 
pense with the necessity of introducing language 
at all. Ideas, says Condillac, are but transformed 
sensations ; and his disciple, Destutt de Tracy, 
has carried the doctrine to its fullest development 
in the aphorism penser c'est sentlr. But who ima- 

c 



I 



PROLEGOMENA LOGICA. 



gines language to be essential to sensation? Or 
who does not see that the introduction of such 
an instrument for the purpose of transforming 
our sensations implies the existence of a mental 
power which mere sensation can never confer? 
It is only on the supposition that the concept is 
something distinct from and unlike all the pro- 
ducts of the senses, that the representative symbol 
becomes necessary. Sensation, imagination, and 
memory, so far as the latter is distinct from 
thought , may dispense with its assistance. As 
for the crowning extravagance of Home Tooke, 
who tells us that what are called operations of 
mind are merely operations of language, we have 
only to ask, what makes language operate ? It 
might as reasonably be maintained that a coat is 
not the work of the tailor, but merely of his 
needle. But it is the perpetual error of the sensa- 
tional school to confound the indispensable con- 
dition of a thing with the thing itself. Thought 
is not sensation, though the exercise of the senses 
is a necessary preliminary to that of the under- 
standing. Science is not a well-constructed lan- 
guage, as the skill of the painter is not identical 

So far, namely, as it corresponds to the pvrjfiri, not to the 
avdjxvr](Tis of Aristotle. The neglect of this distinction led 
Condillac to deny that brutes have any memory, since they 
are destitute of language. Aristotle, with more accuracy, 
allows that memory is common to men and brutes, but 
reminiscence peculiar to the former. See De Memoria, ch. 2. 
&. 25. 



PROLEGOMENA LOGICA. 19 

with the goodness of his brushes and colours ; yet 
we must acknowledge that the power of the artist 
could neither have been acquired nor exhibited, 
had these necessary implements been withheld. 

The above view of the relation of thought to 
language is sometimes met by the following 
dilemma. " Language, you say, is essential to 
thought ; yet language itself, if not of divine 
origin, must have been thought out by man. 
You must, therefore, be prepared to defend in its 
utmost rigour the hypothesis of a supernatural 
origin of speech; or you must allow that its in- 
ventor, at least, was a man capable of thinking 
without its aid p ." To solve this dilemma, we need 
not call in aid the curious hypothesis of Condillac, 
who held that the dependence of thought on 
sensation (and by implication on language) was a 
consequence of the fall of Adam : we need only 
observe what actually takes place in the formation 
of language and thought among ourselves. To 
the child learning to speak, words are not the 
signs of thoughts, but of intuitions ; the words 

p See Kousseau, Discours sur Vorigine de Vinegalite 
jparmi les hommes. Premiere Partie. " Franchissons pour 
un moment l'espace immense qui dut se trouver entre le 
pur etat de nature et le besoin des langues; et cherchons, 
en les supposant necessaires, comment elles purent com- 
mencer a s'etablir. Nouvelle difficulty pire encore que la 
precedente : car si les hommes ont eu besoin de la parole 
pour apprendre a penser, ils ont eu bien plus besoin encore 
de savoir penser pour trouver l'art de la parole." 

c2 



20 PROLEGOMENA LOGICA. 

man and horse do not represent a collection of 
attributes, but are only the name of the individual 
now before him. It is not until the name has 
been successively appropriated to various indi- 
viduals, that reflection begins to inquire into the 
common features of the class q . Language there- 
fore, as taught to the infant, is chronologically 
prior to thought and posterior to sensation. In 
inquiring how far the same process can account 
for the invention of language, which now takes 
place in the learning it, the real question at issue 
is simply this : Is the act of giving names to indi- 
vidual objects of sense a thing so completely beyond 
the power of a man created in the full maturity 
of his faculties, that we must suppose a divine 
Instructor performing precisely the same office as 
is now performed for the infant by his mother or 
his nurse ; teaching him, that is, to associate this 
sound with this sight? This question may be 
answered affirmatively or negatively, but in either 
case it has nothing whatever to do with the re- 
lation of language to thought, properly so called r . 

■J See Adam Smith's Considerations concerning the first 
formation of Languages, appended to his Theory of Moral 
Sentiments. 

r On this subject, the following remarks of Maine de Biran 
are well worthy of attention. " Pour que ces premiers 
signes donnes deviennent quelque chose pour l'individu qui 
sen sert, il faut qu'il les institue lui-meme une seconde fois 
par son activite propre, ou qu'il y attache un sens. Ceux qui 
pensent que 1'homme n'eut pu jamais inventer le langage, si 



PROLEGOMENA LOG1CA. 21 

In relation to this question, the reader must be 
careful not to confuse Language with Articulations. 
The case of the deaf and dumb, so often quoted as 
an instance of thought without language, is in this 
respect utterly irrelevant. The education of these 
persons consists in the substitution of a system of 
signs addressed to the eye or the hand in the place 
of one addressed to the ear. This system performs 
precisely the same office in relation to them that 
speech performs in the ordinary mental develop- 
ment of children : it constitutes, in fact, their 
language. They are thus in no respect an excep- 



Dieu meme ne le lui eiit donne ou revele, ne me semblent 
pas bien entendre la question de l'institution du langage ; ils 
confondent sans cesse le fond avec les formes. Suppose que 
Dieu eut donne a lliomme une langue toute faite ou un 
systeme parfait de signes articules ou ecrits propres a ex- 
primer toutes ses idees ; il s'agissait toujours pour 1'homme, 
dattribuer a chaque signe sa valeur ou son sens propre, 
c'est-a-dire d'instituer veritablement ce signe avec une in- 
tention et dans un but concu par l'etre intelligent, de meme 
que l'enfant institue les premiers signes quand il transforme 
les cris qui lui sont donnes par la nature en veritables signes 
de reclame. 

La difficulty du probleme psychologique, qui consiste a 
determiner les facultes qui ont du concourir a l'institution du 
premier langage, subsiste done la meme, soit que les signes 
qui sont la forme et comme le materiel de ce langage aient 
ete donnes ou reveles par la supreme intelligence, soit qu'ils 
aient ete inventes par 1'homme ou suggeres par les idees ou 
les sentimens dont ils sont lexpression." Nouvelles Consi- 
derations sur les rapports du physique et du moral de Vhomme, 
p. 93. 



22 PROLEGOMENA LOGICA. 

tional case; and the whole question has to be con- 
sidered on general not on special data. I cannot 
perceive any other man's thoughts as they pass in 
his mind : I can only infer their existence from 
perceptible signs ; and this presupposes an esta- 
blished system of communication. The only valid 
method of investigating the relation between 
thought and speech is to examine the only in- 
stances in which both elements are presented, the 
operations of my own consciousness. Accepting 
what is there given in combination,, I must en- 
deavour by analysis to ascertain how much of the 
compound phenomenon is necessary, and how much 
accidental. 

The concept, as thus described, is the charac- 
teristic feature of Thought proper, as distinguished 
from other facts of consciousness : and the think- 
ing process may be adequately defined as the act 
of knowing or judging of things by means of concepts 5 . 
It remains to inquire what, according to this de- 
finition, must be the limits within which Thought 



5 " Der Verstand iiberhaupt kann als ein Vermogen zu ur- 
tlieilen vorgestellt werden. Demi er ist nach dem Obigen ein 
Vermogen zu denken. Denken ist das Erkenntniss durch 
Begriffe." Kant, Entitle der rein. Tern. (p. 70.) An exact 
adherent of Kant would regard the definition given in the 
text as tautological , for with him the provinces of Thought 
and Judgment are coextensive, and all judgment requires 
concepts. But as in the following remarks the province of 
judgment is extended beyond that of thought, the limitation 
becomes necessary. 



PROLEGOMENA LOGICA. 23 

is operative, and what consequently will be the 
distinguishing character of its laws. 

Thought is only operative within the field of 
possible experience; i. e. upon such objects as can 
be presented in an actual intuition or represented 
in an imaginary one. For the concept is the result 
of data furnished by intuition ; and its legitimacy, as 
an object of thought, must be tested by reference 
to the same data. It is true that the concept itself, 
as such, cannot be presented intuitively ; but it must 
contain no attribute which is incompatible with the 
intuitive presentation of its object. The concept 
is not itself individual, but it must comprehend 
such attributes as are capable of individualization, 
such as can coexist in an object of intuition. The 
notion of a triangle, as a rectilinear figure of three 
sides, does not itself contain the attributes of 
equilateral, isosceles, or scalene ; but it is capable 
of being combined with any one of the three in a 
perceived or imagined figure. But a rectilinear 
figure of two sides is, by the application of the same 
test, shewn to be no concept at all. So long as 
we merely unite the attributes in speech, without 
attempting to combine them in an individual object, 
we may not be aware that we are talking nonsense; 
the attempt to imagine the figure shews at once 
the incompatibility of the attributes. This, then, is 
the criterion of positive thinking. A form of words, 
uniting attributes not presentable in an intuition, 
is not the sign of a thought, but of the negation 



24 PROLEGOMENA LOGIC A. 

of all thinking. Conception must thus be carefully 
distinguished, as well from mere imagination, as 
from a mere understanding of the meaning of 
words fc . Combinations of attributes logically im- 
possible may be expressed in language perfectly 
intelligible. There is no difficulty in understand- 
ing the meaning of the phrase bilinear figure, or 
iron-gold. The language is intelligible, though the 
object is inconceivable. On the other hand, though 
all conception implies imagination, yet all imagin- 
ation does not imply conception. To have a con- 
ception of a horse, I must not only know the 
meaning of the several attributes constituting the 
definition of the animal, but I must also be able to 
combine those attributes in a representative image; 
that is, to individualize them. This, however, is 
not mere imagination, it is imagination relatively 
to a concept. I not only see as it were the image 
with the mind's eye, but I also think of it as a 
horse, as possessing the attributes of a given con- 
cept, and called by a name expressive of them. 
But mere imagination is possible without any such 
relation. My mind may recall a sensible impres- 

1 These have been confounded by others besides Eeid. 
Thus Aldrich, after denning Simple Apprehension as nudus 
rei conceptus intellectivus, proceeds, "Si quis dixerit Triangulum 
cequilaterum esse cequiangulum, possum Apprehensioni Sinrplici 
incomplexa intelligere quid sibi velint singula Orationis hujus 
vocabula." Apprehension in this sense is not a logical pro- 
cess at all, and is not governed by any of the laws of logical 
thinking. Cf. Hamilton on Keid, p. 377. 



PROLEGOMENA LOGICA. 25 

sion, on whose constituent features I have never 
reflected, and relatively to which I have never 
formed a concept or applied a name. Imagination 
would be possible in a being without any power of 
distinguishing or comparing his presentations ; it 
is compatible with an ignorance or forgetfulness of 
the existence of any presentations, save the one 
represented by the image. Conception, in its 
lowest degree, implies at least a comparison and 
distinction of this from that. Conception proper 
thus holds an intermediate place between the 
intuitive and symbolical knowledge of Leibnitz, 
being a verification of the latter by reference to 
the former. 

The above remarks will necessitate some modi- 
fication of the doctrines ordinarily taught in logical 
treatises concerning general notions, or, as they 
are commonly though not very happily called, 
abstract ideas. We are told that the mind ex- 
amines a number of individual objects, agreeing in 
some features and differing in others, that it sepa- 
rates the points in which they agree from those in 
which they differ, and makes, of the former only, 
an abstract idea or general notion, which is in- 
differently applicable to all the individuals from 
which it was derived, and by virtue of which they 
are all called by a common name. 

The reality of this process of Abstraction u , and 

" Drobisch observes that the term Abstraction is used 
sometimes in a psychological, sometimes in a logical sense. 



26 PROLEGOMENA LOGICA* 

of the idea to which it is supposed to give rise, 
has been matter of considerable controversy among 
modern philosophers. Bishop Berkeley, and sub- 
sequently Hume, denied altogether the possibility 
of such an operation, on the following grounds. 
The general idea of a triangle, it was argued by 
Locke v ,is an imperfect idea, wherein parts of several 
different and inconsistent ideas are put together. 
As limited to no particular kind of triangle, but 
comprehending all, it must be neither oblique nor 
rectangle, neither equilateral, equicrural, nor sca- 
lene, but all and none of these at once. The 
abstract idea, as thus described, Berkeley easily per- 
ceived to be self-contradictory, and the doctrine 
suicidal. " I have a faculty," he says, " of ima- 
gining or representing to myself the ideas of those 
particular things I have perceived, and of variously 
compounding and dividing them. I can imagine a 
man with two heads, or the upper parts of a man 
joined to the body of a horse. I can consider the 
hand, the eye, the nose, each by itself, abstracted 
or separated from the rest of the body. But then 

In the former, we are said to abstract the attention from 
certain distinctive features of objects presented, [abstrahere a 
differ entiis.) In the latter, we are said to abstract certain 
portions of a given concept from the remainder, (abstrahere 
differentias.) The former sense must be understood here, 
where we are considering the mental process by which con- 
cepts are formed. To the latter, as a conscious process of 
thought, the following remarks do not apply. 
v Essay, book iv. ch. 7. §. 9. 



PROLEGOMENA LOG1CA. 27 

whatever hand or eye I imagine, it must have some 
particular shape and colour. Likewise the idea of 
man that I frame to myself, must be either of a 
white, or a black, or a tawny, a straight, or a 
crooked, a tall, or a low, or a middle-sized man. 
To be plain, I own myself able to abstract in one 
sense, as when I consider some particular parts or 
qualities separated from others, with which though 
they are united in some object, yet it is possible 
they may really exist without them. But I deny 
that I can abstract one from another, or conceive 
separately, those qualities which it is impossible 
should exist so separated ; or that I can frame a 
general notion by abstracting from particulars in 
the manner aforesaid V 

" It is, I know," continues the Bishop, " a point 
much insisted on, that all knowledge and demon- 
stration are about universal notions, to which I 
fully agree : but then it doth not appear to me 
that those notions are formed by abstraction in the 
manner premised; universality, so far as I can 
comprehend, not consisting in the absolute, positive 
nature or conception of any thing, but in the rela- 
tion it bears to the particulars signified or repre- 
sented by it : by virtue whereof it is that things, 
names, or notions, being in their own nature par- 
ticular, are rendered universal. Thus when I de- 
monstrate any proposition concerning triangles, 
it is to be supposed that I have in view the universal 
x Principles of Human Knowledge, Introduction, §. x. 



28 PROLEGOMENA LOGICA. 

idea of a triangle; which ought not to be understood 
as if I could frame an idea of a triangle which was 
neither equilateral, nor scalenon, nor equicrural. 
But only that the particular triangle I consider, 
whether of this or that sort it matters not, doth 
equally stand for and represent all rectilinear tri- 
angles whatever, and is in that sense universal. .... 
Though the idea I have in view whilst I make the 
demonstration be, for instance, that of an isosceles 
rectangular triangle, whose sides are of a deter- 
minate length, I may nevertheless be certain it 
extends to all other rectilinear triangles, of what sort 
or bigness soever. And that, because neither the right 
angle, nor the equality, nor determinate length of the 
sides, are at all concerned in the demonstration. 
It is true, the diagram T have in view includes all 
these particulars, but then there is not the least 
mention made of them in the proof of the proposi- 
tion And here it must be acknowledged, that 

a man may consider a figure merely as triangular, 
without attending to the particular qualities of the 
angles or relations of the sides. So far he may 
abstract : but this will never prove that he can 
frame an abstract general inconsistent idea of a 
triangle 7 ." On the other hand, it was argued 
by Reid, that if a man may consider a figure simply 
as triangular, without attending to the particular 
qualities of the angles or relations of the sides, he 
must have some conception of this object of his 

y Ibid. §. xv. xvi. 



PROLEGOMENA LOGICA. 29 

consideration ; for no man can consider a thing 
which he does not conceive. He has a conception, 
therefore, of a triangular figure, merely as such; 
and this is all that is meant by an abstract general 
conception of a triangle z . 

In this controversy, the question has been need- 
lessly confused by the vague and inaccurate use of 
terms. Idea has been indifferently employed by 
modern philosophers, to denote the object of 
thought, of imagination, and even (under the re- 
presentative hypothesis) of perception \ Concep- 
tion, again, has not been sufficiently distinguished, 
on the one side, from imagination, and, on the 
other, from a mere understanding of the meaning 
of words, such as is sufficient to carry on a process 
of reasoning. To clear up the point at issue, it 
will be necessary to bear in mind two facts which 
have just been noticed ; viz. firstly, that in every 
complete act of conception, the attributes forming 
the concept are contemplated as coexisting in a 
possible object of intuition ; and, secondly, that all 
concepts are formed by means of signs which have 
previously been representative of individual objects 

z Intellectual Powers, Essay v. ch. 6. 

a As it is sometimes convenient to have a general term 
indifferently applicable to any object of internal conscious- 
ness, I have in the present work occasionally availed myself 
in this extent of the term Idea, rejecting, however, the repre- 
sentative idea of perception. The term, however, has been 
avoided, wherever it is necessary to distinguish between two 
different states of consciousness. 



30 PROLEGOMENA LOGICA. 

only. Berkeley, therefore, is thus far right, that 
we cannot, in any single act of conception, think of 
a triangle as neither equilateral, isosceles, nor 
scalene, nor yet as all three at once ; for such an 
individual triangle is not a possible object of in- 
tuition. But, on the other hand, in different acts 
of conception, we may think of a triangle succes- 
sively as equilateral, isosceles, and scalene ; and in 
every single act we regard it as one or another. 
The concept cannot, at any one time, that is, in 
any one act of thought, contain attributes contra- 
dictory of each other ; but it may, at different 
times, be combined with individual attributes that 
are so contradictory. It can therefore potentially, 
i. e. out of relation to this or that act of con- 
ception, be said, in different points of view, to 
contain all or none of such attributes ; but actually, 
in this or that act of conception, it is limited to 
this or that combination. Berkeley is also in one 
sense right in denying that we gain general notions 
by an operation of abstraction, at least after the 
manner in which this operation is frequently ex- 
plained. Similarities are noticed earlier than dif- 
ferences b ; and our first abstractions may be said 
to be performed for us, as we learn to give the 
same name to individuals presented to us under 
slight, and at first unnoticed, circumstances of 

b A contrary theory on this point lias occasioned most of 
the difficulty which Eousseau professes to find in accounting 
for the origin of general language from proper names. 



PROLEGOMENA LOGICA. 31 

distinction. The same name is thus applied to 
different objects,, long before we learn to analyse 
the growing powers of speech and thought, to ask 
what we mean by each several instance of its 
application, to correct and fix the signification of 
words used at first vaguely and obscurely. To 
point out each successive stage of the process by 
which signs of intuition become gradually signs 
of thought, is as impossible as to point out the 
several moments at which the growing child 
receives each successive increase of his stature. 
The mind, like the body, gains its power by im- 
perceptible degrees, " unseen, yet crescive in its 
faculty," and we find ourselves in the possession 
and exercise of nature's gifts, without observing 
how we acquired them. 

On the other hand, throughout Berkeley's dis- 
sertation, too little notice is taken of the important 
fact, that we can, and in the majority of cases do, 
employ concepts as instruments of thought, with- 
out submitting them to the test of even possible 
individualization. But this is done, not in any 
mere act of conception, but only in the more 
complex operations of thought in which such act 
is presupposed. I cannot conceive a triangle 
which is neither equilateral, nor isosceles, nor 
scalene, but I can judge and reason about a 
triangle, without at the moment trying to conceive 
it at all. This is one of the consequences of the 
representation of concepts by language. The sign 



32 PROLEGOMENA LOGICA. 

is substituted for the notion signified; a step which 
considerably facilitates the performance of com- 
plex operations of thought, but in the same pro- 
portion endangers the logical accuracy of each 
successive step, as we do not,, in each, stop to verify 
our signs. Words, as thus employed, resemble 
algebraical symbols, which, during the process of 
a long calculation, we combine in various relations 
to each other, without at the moment thinking of 
the original signification assigned to each. But 
those who, on this account, would reduce the whole 
of thought to an algebraical computation over- 
look the most important feature, the verification, 
namely, of the result, according to the logical 
conditions of conception, after the algebraical 
process is finished. It may be convenient, in the 
course of a complicated reasoning, to assume the 
logical accuracy of the subordinate parts, and to 
employ their respective symbols on this assump- 
tion. But what the concept gains in flexibility it 
loses in distinctness ; and the logical and alge- 
braical perfections are thus in an inverse ratio to 
each other. It therefore becomes necessary, at 
the end of the process, to submit the result to the 
logical test, to which each step has been tacitly 
supposed to conform ; the test of conceivability, 
or the possible coexistence of the several attributes 
in an object of intuition c . 

c " Plerumque, prsesertim in analysi longiore, non to tarn 
simul naturam rei intuemur, sed rerum loco signis utimur, 



PROLEGOMENA LOGICA. 33 

In admitting the above test, we do not accede 
to the ultra-sensationalism of Condillac, nor even 
to the modified doctrine of Laromiguiere, who 
derives from the senses the whole matter of our 
knowledge. Individualize your concepts, does not 
mean sensationalize them, unless the senses are 
the only sources of presentation. If I am imme- 
diately conscious, for example, of an exercise of 
will, as an individual act taking place within me, 
the phenomena of volition become a distinct class 
of presentations, coordinate with, not subordinate 
to, those of the senses, and capable, like them, of 
being represented by the imagination and thought 
upon by the understanding. If I am conscious 
of emotions of joy or sorrow, of anger or fear, 
existing as present individual states of mind, 
distinct from sensible impressions, these, in like 
manner, must be considered as data for thought, 
furnished by intuition. If, on the perception of 

quorum explicationem in praesenti aliqua cogitatione com- 
pendii causa solemus prsetermittere, scientes, aut credentes 
nos earn habere in potestate : ita cum chiliogonum, seu poly- 
gonum niille sBqualium laterum cogito, non semper naturam 
lateris, et aequalitatis, et millenarii (seu cubi a denario) con- 
sidero, sed vocabulis istis (quorum sensu obscure saltern, 
atque imperfecte menti obversatur) in animo utor loco 
idearum, quas de iis habeo, quoniam memini me significa- 
tionem istorum vocabulorum habere, explicationem autem 
nunc judico necessariam non esse ; qualem cogitationem 
csecam, vel etiam symbolicam appellare soleo, qua et in 
Algebra, et in Arithmetica utimur, imo fere ubique." Leib- 
nitz, Meditationes de Cognitione, Veritate et Ideis. 



34 PROLEGOMENA LOGICA. 

certain individual acts performed by myself or by 
another, I am immediately conscious of an idea of 
right or wrong, I have again a distinct class of 
intuitions, simple and ^indefinable, the laws and 
common features of which may furnish matter of 
further reflection, but the existence of which, as 
individual facts, is the indispensable condition of 
all moral speculation, 

The possibility, therefore, of any branch of sci- 
entific inquiry depends upon the psychological 
question, how many presentative faculties has man A P 

d I have purposely adopted this expression, though in some 
respects objectionable, as affording an opportunity of saying 
a few words on a recent psychological controversy. Herbart 
rejects the whole theory of mental inherent faculties as 
chimerical, and has in consequence aimed some severe blows 
at the Psychology of Kant. But in fact it is only the Rational 
Psychology which Kant exploded, which is open to this 
attack. It may be that in mental, as in physical mechanics, 
we know force only from its effects ; but the consciousness of 
distinct effects will then form the real basis of Psychology. 
The faculties may then be retained as a convenient method 
of classification, provided the language is properly explained, 
and no more is attributed to them than is warranted by con- 
sciousness. The same consciousness which tells me that 
seeing is distinct from hearing, tells me also that volition is 
distinct from both; and to speak of the faculty of will does 
not necessarily imply more than the consciousness of a 
distinct class of mental phenomena. No one but an advocate 
of the grossest materialism could understand such an ex- 
pression as implying numerically distinct organs of mind, as 
of body. The Psychology of Herbart has hardly been long- 
enough in existence to produce its ultimate consequences ; 
but there are features in his mode of treating the subject 



PROLEGOMENA LOGICA. 35 

Every such faculty may furnish distinct materials 
for thought. Physical Science is possible, if the 
senses present us with material phenomena, whose 
relations and laws thought may investigate. Moral 
Science is possible, if we are presented with the 
fact of moral approbation and disapprobation of 
this or that action, in itself, and for its own sake ; 
and the question for thought to investigate is, 
whence do these feelings arise, and on what laws 
are they dependent ? iEsthetical Science is again 
possible as a distinct branch of inquiry, if the 
emotions arising from the contemplation of beauty 
in the works of nature or of art can be shewn to 
be distinct from any communicated by their mere 
relation to the senses. And Metaphysics must 
submit to the same criterion. Rational Cosmology 
and Rational Psychology are possible, only if 
Matter and Mind, as distinct from their several 
phenomena, can be shewn to be in any way pre- 
sented, as the objects of an immediate intuition. 

This distinction between the presentations of 
intuition and the representations of thought, which 
is thus the key to all the most valuable appli- 
cations of Psychology, is intimated with more or 
less accuracy in the writings of several modern 

more objectionable than any which he reprehends in Kant. 
A statical and dynamical theory of representations, above and 
below the threshold of consciousness, may have a physiological 
value ; but, in Psychology, seems almost necessarily to lead 
to Materialism. 

d2 



36 PROLEGOMENA LOGICA. 

philosophers. The often-quoted passage of Locke, 
in which the operations of thought are compared 
to the productions of art, furnishes in this respect, 
when understood in its proper latitude, an unex- 
ceptionable description of the respective provinces 
of the intuitive and discursive faculties. " It is 
not in the power of the most exalted wit, or en- 
larged understanding, by any quickness or variety 
of thought, to invent or frame one new simple 
idea in the mind. The dominion of man, in this 
little world of his own understanding, being much 
the same as it is in the great world of visible 
things ; wherein his power, however managed by 
art and skill, reaches no farther than to compound 
or divide the materials that are made to his hand; 
but can do nothing towards the making the least 
particle of new matter, or destroying one atom of 
what is already in being 6 ." The Ideas of Sensation 
and Ideas of Reflection of the same philosopher, 
however unfortunate may be the original choice 
of terms, and however inconsistent their subsequent 
employment, point correctly enough to the two 
great sources of external and internal intuition f . 
A further step in accuracy is gained in the Im- 

• Essay, b ii. ch. 2. §. 2. 

f Reflection, in consistency with etymology and practice, 
ought to have been limited to the operations of thought; in 
which sense we can reflect upon sensible objects as upon all 
other things. Locke only escapes from Reid's criticism on 
this point, by using reflection improperly, as Stewart has 
observed, as synonymous with [internal] consciousness. 



PROLEGOMENA LOGICA. 37 

pressions and Ideas of Hume, though the dis- 
tinction loses most of its value in his hands, by 
the absurd ground of distinction which he has laid 
down between them, and by the unfortunate 
metaphor which declares every idea to be an 
image of an impression g . Kant, who took up 
the discussion where Hume left it, with the 
advantage of a new philosophical language, un- 
encumbered with the associations of earlier sys- 
tems, is the earliest philosopher whose writings 
have disentangled the confusion universally follow- 
ing on the use of the term idea, and exhibited this 
most important distinction with any degree of 
accuracy and precision \ It is one of the most 

g According to Hume, Ideas and Impressions differ from 
each other only in their different degrees of force and vivacity; 
and Belief he defines as " a lively idea associated with a 
present impression;" a doctrine which almost justifies the 
sarcastic application of Eeid, " it will follow, that the idea of 
a lion is a lion of less strength and vivacity. And hence may 
arise a very important question, whether the idea of a lion 
may not tear in pieces and devour the ideas of sheep, oxen, 
and horses, and even of men, women, and children." 

h In this respect, nothing can be more unfair than Stewart's 
sneers at the obscurity and new technical language of Kant. 
The philosophical terms of English and French writers are 
derived from the same source and subject to the same varieties 
of application. The purism of German writers has given to 
all subsequent thinkers the inestimable advantage of contem- 
plating the same thoughts under a new phraseology, and 
with new associations of etymology and metaphor; an ad- 
vantage which no one has appreciated more highly, or ex- 
plained more happily, than Stewart himself, on another 



38 PROLEGOMENA LOGICA. 

valuable principles of the Critical Philosophy, that 
the understanding has no power of intuition ; a 
principle which does not, however, necessitate the 
adoption of the Kantian division of the mental 
faculties, nor even the determination of the 
question, whether the mind possesses numerically 
distinct faculties at all. It simply means, that 
the act of Thought cannot create its own object ; 
that, being mediate and representative, it requires 
to be based on an immediate and presentative fact 
of consciousness. 

It cannot therefore be maintained that the senses 
are the sole criteria of truth and of reality, unless 
we assume, in defiance of all consciousness, that 
there exist no immediate mental phenomena, but 
those communicated by sensation. Any one pre- 
sentation is as true and as real as any other. 
Falsehood and unreality can only begin with 
thought. The immediate judgment of present- 
ation, that I am at this moment conscious of a 
certain object, is equally true as regards any class 
of presentations. Unreality, in this case, can only 
consist in the distinctness of one class of present- 
ations from another, which latter we have arbi- 
trarily selected as the test of reality ; and falsehood, 
in the assertion of the identity of distinct classes, or 

occasion. As it is impossible to comply exactly with the 
precept of Locke, to judge of ideas in themselves, their names 
being wholly laid aside, the next best course is, to examine 
them, as far as possible, through the medium of two inde- 
pendent languages. 



PROLEGOMENA LOGICA. 39 

of the distinctness of identical ones. But such a 
selection or assertion involves an act of thought ; it 
is a judgment concerning intuitions as classified 
under certain concepts. If I choose arbitrarily to 
select the senses as the sole test of reality, the 
phantasms of imagination are so far unreal; but 
their unreality implies no more than that they are 
not perceived by the senses. If I say, " a centaur 
exists as an image in my mind, therefore it exists 
in nature/' the assertion is false, because, by an act 
of thought, I judge that to be an object of possible 
sense, which is only given to me as an object of 
imagination: its reality in relation to the latter 
faculty remains undisturbed. 

This view of the reality of all presentations, as 
such, could not indeed be consistently held by the 
advocates of a representative theory of perception. 
If, in all intuition, I am immediately conscious only 
of certain ideas or modifications of my own mind, 
I am reduced to the alternative, either of disbe- 
lieving the existence of an external world altogether, 
or of drawing a distinction between such ideas as 
are representative and indicate the existence of 
objects without my mind, and such as are purely 
imaginary and have no objective reality correspond- 
ing 1 . The former will then be distinguished as 
real, the latter as unreal presentations. But if, in 
perception, I am immediately and presentatively 
conscious of a non-ego, (and such is the soundest 

1 See Locke, Essay, h. iv. ch. 4. §. 3 — 12. 



40 PROLEGOMENA LOGICA. 

view, both in common sense and in philosophy,) the 
representative idea and its supposed claim to su- 
perior reality vanishes altogether. Every present- 
ation is real in itself, some as immediately informing 
me of the existence of states of my own mind, 
others as immediately informing me of the existence 
of objects without ; and my judgment about each 
is equally true, when I assert it to be what it is, 
and equally false, when I assert it to be what it is 
not. In this respect, the philosophers of the school 
of Common Sense have not always consistently 
adhered to their fundamental principle, in the 
distinction which they have drawn between per- 
ception and imagination k . 

But though it is not true that the whole matter 
of knowledge is furnished by the senses, it cannot 
be denied that it is entirely furnished by the pre- 
sent ative faculties. And this may throw some light 
on a distinction, concerning which there frequently 
exists considerable confusion, the distinction be- 
tween what are, vaguely enough, termed positive 
and negative ideas 1 . A positive intuition is one 

k See Reid, Inquiry, ch. ii* §. 3, and the antagonist remarks 
of Stewart, Elements, vol. i. ch. 3. Both discussions might have 
been cleared of some confusion, by determining accurately 
what is meant by reality in presentations. 

1 A pupil of mine once asserted to me, on the authority of 
another tutor, that voluntary action was a negative idea, mean- 
ing the absence of restraint. If his arms had been strapped 
tight to his sides from the day of his birth, he would have 
had a negative idea only of the voluntary motion of the limb. 



PROLEGOMENA LOGICA. 41 

which has been presented to us in actual conscious- 
ness ; a positive concept is one formed from such 
presentations. A negative intuition is one which 
has never been actually presented to us, though 
we may have been conscious of others of the same 
class ; and a negative concept, which is in fact no 
concept at all, is the notion which we endeavour 
to form of such presentations. The nature of 
the presentation will of course depend upon the 
faculty to which that class of intuitions belongs. 
If I have never seen objects of any other colour 
than white and red, I have a positive idea of 
these, a negative idea of blue and yellow. If 
I had all my lifetime been subject to coercion, 
and had never performed an act of volition, I 
should have a negative idea of free agency. If I 
had never in my life found my volition opposed, 
I should have a negative idea of coercion. As it 
is, I have a positive idea of both. I desire to thrust 
my arm out in open space, and my desire is carried 
into effect. Here is the positive consciousness of 
freedom. I try to thrust it through a wall, and 
am resisted. Here is the positive consciousness of 
coercion. When Locke declared infinite space 
and infinite duration to be negative ideas, he was 
right, if we grant his hypothesis of their origin. 
The former he derived from sensation ; and all the 

As it is, the idea of voluntary action is as positive as it can 
possibly be, being every moment presented to us in actual 
consciousness. 



42 PROLEGOMENA LOGICA. 

space which we can actually perceive by the senses 
is finite : the latter he derived from reflection ; 
and every duration which we have personally expe- 
rienced is finite also. Those who do not accede 
to his conclusion ground their dissent on a denial 
of his premises m . The language in which the 
concept is expressed is in this respect altogether 
indifferent. We may speak of the same act as 
voluntary, or not constrained, as compulsory, or not 
voluntary. The test of its positive or negative 
character is to be found in the question, Has it 
ever been realized in an intuitive presentation ? 

If thought is operative only within the field of 
possible experience, it follows, that we are not en- 
titled, in any act of thought, to add to the data given 
in the concept, without a fresh appeal to intuition. 
I have in my mind the notion of a centaur, as a 
creature with the upper parts of a man and the lower 
parts of a horse. But this concept does not in itself 
contain the attribute of existence in space as an 
object of possible perception. I am therefore not 
warranted in thinking of the centaur as so existing, 
until the attribute is supplied from its proper source 
of presentation, which in this case is sensible ex- 
perience. If my notion of man does not contain 
the attribute of mortality, I may think of man as 
mortal or as immortal, but I cannot determine 
which of these judgments is true; i. e. is in accord- 
ance with the corresponding intuition, without 

m Cf. Cousin, Histoire de la Philosophic, lecon xviii. 



PROLEGOMENA LOGICA. 43 

comparing them with the fact as presented by 
experience. In the mere notion of two straight 
lines, it is not contained that they cannot inclose 
a space; and in the mere notions of the numbers 
7 and 5, it is not contained that their sum is 
12. Neither of these judgments therefore can 
be determined to be true, without an appeal to 
some fact or other of intuition. This limitation of 
the province of thought implies some important 
consequences, which will appear when we come to 
consider the character of the laws of pure thinking 
recognised by Logic. 

Before taking leave of this part of our subject, it 
may be useful to point out one or two questions of 
controversy, to which the distinction between 
Thought and other facts of consciousness may be 
applied with advantage. 

It has been remarked by Sir William Hamilton 11 , 
that the whole controversy of Nominalism and 
Conceptualism is founded on the ambiguity of the 
terms employed ; on the want, that is, of an accurate 
distinction, such as is furnished by the German 
Anschauung and Begriff, between the individual 
intuitions of sense and imagination, and the general 
concepts of the understanding. We may observe 
further, that the controversy between Nominalism 
and Realism may be, if not absolutely decided, 
at least considerably simplified, by attending 
to the same distinction. Some recent critics, in 

n Reid's Works, p. 412. 



44 PROLEGOMENA LOGICA. 

examining this question, have managed to introduce 
additional confusion into what was sufficiently- 
confused before. It is asked, for example, whether 
the great division of animal, vegetable, and mineral 
is not to be regarded as the work of nature, rather 
than as the arbitrary product of man's classifica- 
tion . Undoubtedly: but what has that to do with 
the question of the existence of Universals out of 
the mind? We admit, that is, that nature has 
stamped on certain locally distinct individuals, a 
number of prominent features of resemblance, which 
cannot fail to strike the eye of an observer. But has 
she thereby produced any thing more than one set 
of attributes existing in one individual in one place, 
and another similar set existing in another indi- 
vidual in another place ? But when, by an act of 
mind, we have abstracted from the existence in 
space under which all objects of sense are pre- 
sented, and, by virtue of that abstraction, have 
advanced from individual similarity to specific unity, 
from the similar attributes of several objects to the 
mutual relation of all, the results of the process 
can only be regarded as the offspring of our minds. 
This consideration does not indeed prove decisively 
the impossibility of universals a parte Rei, but it 
shews that no argument in favour of their existence 
can be drawn from the observed uniformities of 
nature. 

Another subject of dispute between different 
° See Woolley's Logic, p. 69. 



PROLEGOMENA LOGICA. 45 

schools of philosophy is, What are the limits of 
definition ? The Scholastic Logicians, holding 
that definition was by genus and differentia, very 
consistently laid it down as a canon, that no object 
was definable which could not be regarded as a 
Species. Summa genera and individuals were by 
this rule incapable of definition. On the other 
hand, Descartes and Locke, rejecting this re- 
striction, maintain that simple ideas alone cannot 
be denned. Both are right, according to their 
different meanings of definition. With the former, 
it signifies the resolution of a complex general 
concept, into the simpler concepts which it com- 
prehends. With the latter, it is the resolution of 
a complex individual object of sense, into the sim- 
pler objects of which it is composed. The one is 
a mental analysis of notions, the other a sensible 
analysis of intuitions. No definition, as Locke 
truly observes, will convey the idea of whiteness 
to a blind man ; i. e. it will not enable him to form 
a sensible image of the colour. But no definition 
(in the scholastic sense) was ever intended to 
accomplish this object. The far-famed animal 
rationale f does not do it for man ; and for the very 
sufficient reason, that concepts, as such, are not 
capable of being presented in sense or imagin- 
ation. If the purpose of logical definition were to 
enable us to form an idea, i. e. a representative 
image of an object, pointing it out with the finger 
would be a far more satisfactory definition than 



46 PROLEGOMENA LOGICA. 

any verbal analysis p . But ideas, in this sense, have 
no connection with logical definition. Locke's 
ideas of sensation, simple or complex, are all 
excluded from the province of definition, as being 
individuals, i. e. as not being concepts at all. 
On the other hand, the concept whiteness, as a 
species of colour, is capable of definition by its 
optical differentia, as a colour produced by equal 
mixture of the simple rays. An example adduced 
by Descartes, as well as by Locke and Leibnitz, 
will illustrate the distinction still more clearly. 
The concept of a chiliogon is a regular polygon 
of 1000 sides. As addressed to the sense, this 
definition would not enable any man to distinguish 
an individual figure of the kind by sight from 
another which had 999 sides ; but, as addressed to 
the understanding, it is sufficient for the demon- 
stration of the mathematical properties of the 
figure. This is one example, among many that 
might be adduced, of the confusion that has arisen 
from the vague and vacillating employment in 
modern philosophy of the term Idea. 

The same distinction will furnish a ground for 
criticising certain popular systems of logical no- 
tation. If Logic is exclusively concerned with 
Thought, and Thought is exclusively concerned 
with Concepts, it is impossible to approve of a 
practice, sanctioned by some eminent Logicians, 

P Arist. Anal. Post. II. 7. ov yap hrj deigei ye rfj ala6t]crei r) r<5 
daKTvXa). Cf. Mill's Logic, vol. i. p. 183. 



PROLEGOMENA LOGICA. 47 

of representing the relation of terms in a syllogism 
by that of figures in a diagram. To illustrate, for 
example, the position of the terms in Barbara, by 
a diagram of three circles, one within another, is to 
lose sight of the distinctive mark of a concept, 
that it cannot be presented to the sense, and 
tends to confuse the mental inclusion of one 
notion in the sphere of another, with the local 
inclusion of a smaller portion of space in a 
larger q . The diagrams of Geometry in this respect 
furnish no precedent ; for they do not illustrate 
the form of the thought, but the matter, not 
the general character of the demonstration as a 
reasoning process, but its special application as a 
reasoning about magnitudes in space. Still less 
is such a practice justified by the test of con- 
ceivability which has been mentioned above, the 
possibility, namely, of individualizing the attri- 
butes comprehended in a concept. For, whereas 

i " Da der Mensch die Sprache hat," says Hegel, " als das 
der Vernunft eigenthumliche Bezeichnungsmittel, so ist es 
ein miissiger Einfall, sich nach einer unvollkommnern 
Darstellungsweise umsehen und damit qualen zu wollen. 
Der Begriff kann als soldier wesentlich nur mit dem Geiste 
aufgefasst werden. Es ist vergeblich, ihn durch Eaumfiguren 
und algebraische Zeichen zum Behufe des ausserlichen Auges 
und einer begrifflosen, mechanischen Behandlungsweise, eines 
Calculs, festhalten zu wollen." While dissenting totally from 
the Hegelian view of Logic, I cannot resist quoting the above 
passage, as applicable to every view of the Science which 
recognises the essential distinction between thought and 
intuition. 



48 PROLEGOMENA LOG1CA. 

that test is employed to determine the conceiv- 
ability of the actual contents of each separate 
concept, the logical diagrams are designed to 
represent the universal relations in which all con- 
cepts, whatever be their several contents, formally 
stand towards each other. The contrast between 
these two, as legitimate and illegitimate appeals to 
intuition, will more fully appear in the sequel. 



CHAP. II. 

ON THE THKEE OPEEATIONS OF THOUGHT. 

Concerning the threefold division of the mental 
operations usually acknowledged by Logicians, it 
has been questioned, whether they are properly to 
be regarded as distinct acts of Thought or not. 
The question may be considerably simplified, by 
discriminating between different principles of 
identity or distinctness, as applicable severally to 
mental and material objects. The only natural 
and necessary principle of distinction between 
objects is the numerical diversity of individuals. 
In this respect, not only the several acts of Simple 
Apprehension, Judgment, and Reasoning, but every 
single act of each class is distinct from every 
other. An act of reasoning which I perform to- 
day is numerically distinct from any act performed 
yesterday, though both may be governed by the 
same laws and applied to the same objects. 
Beyond this, any principle of specific identity or 
diversity is to a certain extent arbitrary and arti- 
ficial. The only ground of distinction between a 
natural and an unnatural classification of indi- 
viduals depends upon the frequency with which 



50 PROLEGOMENA LOGICA. 

we have occasion to view them in this or that 
relation ; in other words, on the respective utility 
of different points of view for certain given pur- 
poses. On this ground, Apprehension, Judgment, 
and Reasoning are rightly and necessarily regarded 
as distinct classes of mental operations, relatively 
to Logic, inasmuch as their several products, the 
Concept, the Judgment, and the Syllogism, exhibit 
distinct logical forms, and require a distinct logical 
treatment. 

Psychologically, the question must be examined 
on somewhat different grounds. It may be urged, 
for example, on the one side, that the several 
operations are the product of the single faculty of 
Comparison; that they are not in act ever separable 
from each other, Apprehension being always ac- 
companied by Judgment, and Judgment by Appre- 
hension, and Reasoning by both ; that the mind, 
one and indivisible, is wholly employed in each. 
On the other side, it may be answered, that acts 
of Comparison may be regarded as specifically 
distinct, as engaged on distinct objects ; that the 
comparison of attributes with each other, of con- 
cepts, immediately in themselves, or mediately with 
a common third concept, are pro tanto distinct 
acts, requiring distinct mental powers ; that the 
same mind is not always equally skilful in all 
three ; and other arguments of the like kind. 
Both these opposite opinions may be accepted as 
true, if we attend to the different points of view 



PROLEGOMENA LOGICA. 51 

which render the decision of all such matters of 
controversy in some degree arbitrary. 

The distinction between the faculties and parts 
of the mind is based on a principle exactly the 
reverse of that by which a similar distinction is 
made relatively to the body. The members of the 
latter are given as locally and numerically dis- 
tinct, and thus furnish a preexisting basis for the 
classification of their several operations. Thus, 
seeing and hearing are distinguished from each 
other, as the operations of the eye and the ear 
respectively ; and the use of the pen, the brush, 
and the chisel may in this point of view be 
classified together, as operations of the hand. 
Whereas, in the mind, the distinctness of the 
operations is itself the ground on which, for mere 
convenience of discussion, we classify and dis- 
tinguish different parts and faculties, as belonging 
to the mind itself. The acts, therefore, must, on 
independent grounds, be determined to be identical 
or distinct, before we unite or separate them, as 
related to the same or diverse mental powers. 

Hence it appears that the classification of opera- 
tions, relatively to distinct mental faculties, is con- 
tingent upon the adoption of some independent 
principle for classifying the same operations in them- 
selves. In the present state of Psychology, much 
must be left to the discretion of individual inquirers ; 
no one division having been so universally adopted 
by philosophers, or having led to such important 

e 2 



52 PROLEGOMENA LOGICA. 

results, as to render imperative its adoption as the 
division /car iijoxqv of psych ologers. But to suppose 
a distinct mental faculty for each of the three 
logical operations > solely on the ground of the 
distinct objects compared in each, is, to say the 
least, to make Psychology unnecessarily compli- 
cated, and to offend against a rule of great weight 
in all systems of classification, Entia non multipli- 
canda prceter necessitatem. As individual acts, every 
distinct exercise of thought is numerically distinct 
from every other, as the act of eating beef to-day is 
numerically distinct from the act of eating mutton 
to-morrow ; but the enumeration of distinct faculties 
of Conception, Judgment, and Reasoning, would 
probably effect as little for the progress of mental 
science, as the distinction of a beef-eating and a mut- 
ton-eating faculty for Physiology a . Another consi- 
deration, and one, if tenable, of more present value in 
the controversy, is the opinion already mentioned ; 
viz. that, in every individual operation of Thought, 
the acts, at least, of Conception and Judgment are 
inseparable from each other. If this be strictly 



a " As sensation, reasoning, volition, memory, &c. are the 
several modes of thinking ; so roasting of beef, roasting of 
mutton, roasting of pullets, geese, turkeys, &c. are the several 
modes of meat-roasting. . . . Just so, the quality or disposition 
of a fiddle to play tunes, with the several modifications of this 
tune-playing quality, in playing of Preludes, Sarabands, Jigs, 
and Gavotts, are as much real qualities in the Instrument, 
as the Thought or the Imagination is in the mind of the person 
that composes them." Memoirs of Scriblerus. 



PROLEGOMENA LOGTCA. 53 

true, the distinction usually maintained between 
the two operations must be regarded as logical 
only, the operations themselves being really iden- 
tical. But this assertion requires some modification, 
owing to an unnoticed ambiguity in the logical and 
psychological acceptation of the terms employed 
in it. 

Extending the terms Apprehension and Judg- 
ment beyond the region of Thought proper b , it may 
be laid down, as a general canon of Psychology, that 
the unit of consciousness is a judgment; in other 
words, that every act of consciousness, intuitive or 
discursive, is comprised in a conviction of the 
presence of its object, either internally in the mind 
or externally in space. The result of every such 
act may thus be generally stated in the proposi- 
tion, " this is here." Consequently, at least with 
reference to the primary and spontaneous, as dis- 
tinguished from the secondary and reflex acts of 
consciousness, it is more correct to describe Appre- 
hension as the analysis of Judgments, than Judg- 
ment as the synthesis of Apprehensions . 

b The division into Simple Apprehension, Judgment, and 
Reasoning is usually given as one of the discursive faculties. 
Yet even Logicians have extended it to the powers of percep- 
tion and imagination. Indeed, these several faculties have 
shared in the confusion arising from the vague use in modern 
philosophy of the term idea. A striking instance is. afforded 
by Wolf, in his account of Apprehension and Judgment. 
Phil. Eat. §. 33—39. 

■ c See Reid, Intellectual Powers, Essay iv. ch. 3. with Sir 
W. Hamilton's Commentary. 



54 PROLEGOMENA LOGICA. 

In a psychological point of view, therefore, it is 
incorrect to describe Simple Apprehension as the 
first operation of the mind. In one sense, indeed, 
the relation of prior and posterior is altogether 
out of place. Chronologically, inasmuch as every 
Apprehension is simultaneous with a Judgment, and 
every Judgment with an Apprehension ; and logi- 
cally, inasmuch as Judgment cannot exist without 
Apprehension, nor Apprehension without Judgment. 
In another sense, however, we may properly say 
that Judgment is prior to Apprehension ; meaning 
that the subject and the object are first given in 
their mutual relation to each other, before either 
of them can itself become a separate object of 
attention. But when a corresponding division is 
adopted of the operations of Thought, properly so 
called, the same order of priority cannot be observed. 
Every operation of thought is a judgment, in the 
psychological sense of the term : but the psycho- 
logical judgment must not be confounded with the 
logical. The former is the judgment of a relation 
between the conscious subject and the immediate 
object of consciousness: the latter is the judgment 
of a relation which two objects of thought bear to 
each other. The former cannot be distinguished 
as true or false, inasmuch as the object is thereby 
only judged to be present at the moment when 
we are conscious of it as affecting us in a certain 
manner ; and this consciousness is necessarily true. 
The latter is true or false, according as the rela- 



PROLEGOMENA LOGICA . 55 

tions thought as existing between certain concepts 
are actually found in the objects represented by 
those concepts or not. The logical judgment 
necessarily contains two concepts, and hence must 
be regarded as logically and chronologically pos- 
terior to the conception, which requires one only. 
The psychological judgment is coeval with the 
first act of consciousness, and is implied in every 
mental process, whether of intuition or of thought. 
It cannot, therefore, be called prior or posterior to 
any other mental operation, for there is no mental 
operation in which it does not take place ; but the 
judgments of intuition are logically and chronolo- 
gically prior to the judgments of thought d . Con- 



d Of the important distinction between chronological and 
logical priority, (the tempore and natura of the scholastic post- 
predicaments,) it will be sufficient to quote one ancient and 
one modern exposition. Aristotle, (for name and thing,) 
Categ. ch. 12. Uporepov erepov erepov \eyerai rerpax&s, Trpcorov pev 
teal Kvpicorara Kara, xpovov, /ca#' 6 npea^vrepov erepov erepov koX 7ra\aio- 
repov \eyerai. . . . Aevrepov be rb pf) avriarpecpov Kara rrjv rov elvai 
aKoXovdrjo-tv, olov rb ev rcbv 8vo rrporepov bvolv pev yap ovrcov aKoXovdel 
evdvs rb ev elvat, evbs be ovros ovk avaymlov dvo elvai. Metaph. viii. 
8. 2. Udarjs 8rj rrjs roLavrrjs nporepa ecrriv r\ evepyeia koi Xoy<a koX rfj 

ovo-Lq' xpdva) S' eo-n pev &s, ean $ a>s ov. Cousin, Programme 
d'un cours de Philosophic " Une connaissance est anterieure 
a une autre dans l'ordre logique, en tant qu'elle l'autorise ; elle 
est alors son antecedent logique. Une connaissance est an- 
terieure a une autre dans l'ordre psychologique, en tant qu'elle 
se produit avant elle dans l'esprit humain ; elle est alors son 
antecedent psychologique." For some admirable applications 
of the above distinction, see the same author's criticism of 
Locke, Cours de Philosophic, lecon 17. 



56 PROLEGOMENA LOGICA. 

ception is a psychological judgment, but not a 
logical one, and is properly ranked as the first 
operation of Thought, inasmuch as it is the simplest. 

As the design of the present essay is not to 
consider Psychology in itself, but Psychology in its 
relation to Logic, I shall content myself with 
accepting the three operations of Thought as they 
are commonly distinguished by Logicians, examin- 
ing them with the view of ascertaining what light 
Psychology can throw on the province and laws 
of each. Whether, in other points of view, and 
relatively to other principles of classification, they 
ought invariably to be distinguished as three sepa- 
rate operations of the mind, is a question which 
I shall not at present discuss further. In relation 
to their several logical products, the three opera- 
tions may be distinguished as follows. 

Conceiving has been already explained as the 
individualizing of certain attributes comprehended 
in a general notion and expressed in a general 
term ; the representation, namely, of such attri- 
butes as coexisting in a possible object of intuition. 
Language, as before observed, is, in its earliest 
operations, a sign, not of concepts, but of in- 
tuitions. Its earliest terms are employed as the 
proper names of individual objects. Conception 
does not take place till after we have learned to 
give the same name to various individuals pre- 
sented to us with certain differences of attributes, 
and hence to associate it with a portion only, not 



PROLEGOMENA LOGICA. 57 

with the whole, of what is presented in each. This 
may be distinguished as Abstraction, a spontaneous, 
though not always a voluntary act, the concen- 
tration of the mind on certain portions only of 
a given object in relation to its name. This 
must not be treated, as is frequently done by 
Logicians, as a conscious process of thought, 
being only a preliminary condition to thinking, 
taking place in the majority of cases uncon- 
sciously, during the gradual acquisition of speech 6 . 
Our names thus gradually acquire a signification, 
being transformed from proper names to appel- 
latives. Finally, the act of conception consists in 
contemplating the attributes thus combined in 
the signification of a name as coexisting, along 
with individual features, in a possible object of 
intuition, and hence, apart from the individual 
features, as indifferently representing all such 
objects. This representative collection of attri- 
butes, combined by means of a sign, is a Concept, 

In the above remarks, the office of language is 
considered as it now exists and is taught, not as it 

e Abstraction, as described by Stewart, Elements, vol. i. 
ch. 4. answers in essential points to what I have here de- 
scribed. It should be observed, however, that by language 
as it now operates, whatever may have been the case in 
its first formation, the question as to what attributes shall 
be abstracted and what retained, is in a great measure deter- 
mined for us. The process must thus be distinguished from 
the voluntary abstraction implied in all operations of thought. 
On Abstraction, as distinguished from Attention, see Tissot, 
Anthropologic, vol. i. p. 142. 



58 PROLEGOMENA LOGICA. 

might possibly have been originally created. We 
do not form our own language, but receive it 
ready formed ; and its teaching, whether true or 
deceitful, whether promoting or distorting the 
right development of the mind, does, as matter of 
fact, impress us from our infancy upwards with 
certain associations, and casts our earliest thoughts 
in a certain mould, from which no future effort 
can wholly emancipate us. I am not now con- 
sidering what might have been the course of our 
mental growth, had we been the original inventors 
of our mother tongue, or if we had been born 
among a people with whom (as in a hypothesis 
of Reid's^ every sound represented a complete 
sentence. Language is not here considered as it 
might have been invented by a conclave of ima- 
ginary philosophers, or as it may have influenced 
the thoughts of Adam in Paradise ; but as it does 
influence the thoughts of children born into the 
world, the offspring of articulately-speaking pa- 
rents. 

As in Conception a single general notion is 
considered in its relation to a possible object of 
intuition, so in Judgment two such notions are 
considered as related to a common object. When 
I assert that A is B, I do not mean that the attri- 
butes constituting the concept A are identical 
with those constituting the concept B ; for this is 

f Correspondence, Letter xi. to Dr. James Gregory. See 
p. 71. of Sir W. Hamilton's edition. 



PROLEGOMENA LOGICA. 59 

only true in identical judgments; but that the 
object in which the one set of attributes is found 
is the same as that in which the other set is found. 
To assert that all philosophers are liable to error 
is not to assert that the signification of the term 
philosopher is identical with that of liable to 
error ; but that the attributes comprehended in 
these two distinct terms are in some manner 
united in the same subject. To ask what con- 
stitutes unity or identity in a subject of attributes 
is to enter on a deep metaphysical question, the 
discussion of which must be postponed to a later 
stage of our inquiry ; it is sufficient for the present 
to observe, that the common language and com- 
mon thought of mankind universally acknowledge 
something of the kind, assuming, whether they 
can explain it or not, that a certain smell and 
colour and form, which are distinct attributes, are 
in some way related, as parts or qualities, to some 
one thing which we call a rose ; and that, when 
I assert that the rose is fragrant, I imply that 
the thing which affects in a certain way my power 
of sight is in some manner identical with that 
which affects in a certain way my power of smell. 
The metaphysical problem thus lies at the bottom 
both of Conception and of Judgment, and, whether 
it admits of satisfactory explanation or not, must 
be included as a fact in any description of the 
several operations of Thought. 

Reasoning is the most complex of the three 



60 PROLEGOMENA LOGICA. 

operations, as in it two concepts are determined 
to be in a certain manner related to each other, 
through the medium of their mutual relations to a 
third concept. This operation is therefore treated 
last in order g . The nature of the several relations 
asserted in the premises and deduced in the con- 
clusion, are the same as those implied in Judgment, 
and lead to the same metaphysical difficulties. 
These, together with the logical and psychological 
character of the Laws of Thought, will be con- 
sidered in a future chapter. For the present, it 
will be sufficient to attempt, in accordance with 
the above observations, a definition of the products 
of the several acts of Thought, the Concept, the 
Judgment, and the Syllogism, the legitimate objects 
of Formal Logic. 

A Concept is a collection of attributes, united 
by a sign, and representing a possible object of 
intuition. 

A Judgment is a combination of two concepts, 
related to one or more common objects of possible 
intuition. 

s " Judicium notiones conjungit vel separat, adeoque eas 
supponit. Eatiocinando ex notionibus et judiciis prseviis 
elicitur judicium ulterius, adeoque ratiocinatio notiones et 
judicia supponit. Ergo notio est operatio prima, judicium 
secunda, discursus tertia." Wolf, Phil. Bat. §. 53. But 
Wolf, as before observed, has not accurately distinguished 
between the perceptive and discursive faculties. His remark 
is true, though only in a much narrower sense than that 
in which he designed it. 



Prolegomena logica. 61 

A Syllogism is a combination of two judgments, 
necessitating a third judgment as the consequence 
of their mutual relation. 

The definition above given of a Judgment 
renders necessary a few remarks on a class of 
propositions, whose true logical character has been 
considerably misapprehended by eminent autho- 
rities. According to the above definition, every 
judgment in Logic must be regarded as a com- 
bination of concepts ; every term of such judg- 
ment, as the sign of a concept. This is no less 
true of singular than of common judgments, and 
the neglect of it has given rise to some errors in 
the logical treatment of propositions. " Proper 
names," says Mr. Mill, iC denote the individuals 
who are called by them ; but they do not indicate 
or imply any attributes as belonging to those in- 
dividuals. When we name a child by the name 
Mary, or a dog by the name Caesar, these names 
are simply marks used to enable those individuals 
to be made subjects of discourse. It may be said, 
indeed, that we must have had some reason for 
giving them those names rather than any others : 
and this is true ; but the name, once given, be- 
comes independent of the reason. A man may 
have been named John, because that was the 
name of his father ; a town may have been named 
Dartmouth, because it is situated at the mouth of 
the Dart. But it is no part of the signification of 
the word John, that the father of the person so 



62 PROLEGOMENA LOGIC A. 

called bore the same name ; nor even of the word 
Dartmouth, to be situated at the mouth of the 
Dart h ." 

These remarks are true, so far as the name 
alone is concerned, or as regards the reason of its 
being imposed, at a certain time, on a certain man. 
But then the man, as an individual existing at 
some past time, cannot become immediately an 
object of thought, and hence is not, properly- 
speaking, the subject of any logical proposition. 
If I say, " Caesar was the conqueror of Pompey, 5 ' the 
immediate object of my thought is not Caesar as 
an individual existing two thousand years ago, 
but a concept now present in my mind, com- 
prising certain attributes, which I believe to have 
coexisted in a certain man. I may historically 
know that these attributes existed in one indi- 
vidual only ; and hence my concept, virtually 
universal, is actually singular, from the accident 
of its being predicable of that individual only. 
But there is no logical objection to the theory 
that the whole history of mankind may be repeated 
at recurring intervals, and that the name and 
actions of Caesar may be successively found in 
various individuals at corresponding periods of 
every cycle. 

" Alter erit turn Tiphys, et altera quae veliat Argo 
Delectos heroas; erunt etiam altera bella; 
Atque iterum ad Tro-jam magnus mittetur Achilles." 

h Mill's Logic, vol. i. p. 40. 



PROLEGOMENA LOGICA. 63 

These remarks will suggest a correction of the 
ordinary logical account of the quantity of pro- 
positions, which should have been made long ago. 
The subjects of all logical judgments are concepts : 
the true singular proposition in Logic is not one 
in which the concept is materially limited to an 
individual by extralogical considerations, but one 
in which it is formally so limited by a sign of indi- 
viduality. In scholastic language, only individua 
demonstrativa, and not, as is vulgarly taught, 
individua signata, are properly the subjects of 
singular propositions 1 . Indefinite, or, as they 
should rather be called, indesignate k propositions 
are an anomaly in Logic, no less when the subject 
is a singular, than when it is a common term. In 
both, the quantity can only be known by the 
matter, and, in both, an appeal to the matter is 
extralogical. 

The same considerations will also shew the 
propriety of Aristotle's limitation of the logical 
verb to the present tense only. All thought is 
a consciousness of present mental acts, and its 
object is not the past event, but the present con- 

1 Cf. Fries, System der Logik, §. 22. His principle is 
sound, though some of his instances are inaccurate. 

k Properly speaking, particular propositions are indefinite, 
singulars and universals definite. For when I say, Some 
A is B, I leave it altogether undetermined how many, and 
whether any given A is included or not. For this reason, it 
is better to adopt the term indesignate, suggested by Sir 
W. Hamilton. 



64 PROLEGOMENA LOGICA. 

cept of it. Hence the office of the verb in Logic 
is not to declare the past or future connection of 
an attribute with its subject in the represented fact, 
but to declare the present coexistence of two con- 
cepts in the representative act of thought K 

Before quitting this portion of the subject, it 
will be desirable to compare the conclusions arrived 
at with those of two eminent philosophers, from 
both of whom they appear, verbally at least, to 
differ in a slight degree. 

Locke's well-known definition of knowledge, 
" the perception of the agreement or disagreement 
of two ideas," has been somewhat severely com- 
mented on by his illustrious critic, M. Cousin m . 
The French philosopher shews clearly that, in 
many of our judgments, we cannot be said to 
have distinct notions of the terms united, prior to 
pronouncing on the fact of their agreement. The 
distinctions drawn in the preceding remarks will, 
I think, furnish a ground for a more exact decision 
of the point at issue, than has been given either by 

1 " Copula non est nisi verbum substantivum prsesentis tem- 
poris. Denotat enim nexum inter subjectum et praedicatum 
intercedentem, qualis nempe reprsesentatur in ideis nostris. 
Cum igitur in omni judicio nexus ille semper sit aliquid 
prsesens, copula non esse potest nisi verbum substantivum 
praesentis temporis." Wolf, Phil. Rat. §. 202. 

m Cours de Philosophie, lecon 23. Compare Jouffroy's Reid, 
Preface, p. 130, 133, sqq. For other criticisms, see Reid, 
Intellectual Powers, Essay I. ch. 7. Essay VI. ch. 3. Leibnitz, 
Nouveaux Essals, IV. 1. 



PROLEGOMENA LOGICA. 65 

the English philosopher or his French censor. 
Locke's definition abounds in verbal inaccuracy, 
for which, however, the author is not entirely re- 
sponsible, as it is partly owing to the unsettled sig- 
nification, in his day, of philosophical terms, which 
have since been more accurately determined. Taking 
Perception in the strict sense to which it has been 
determined by Reid and his successors, it is not 
correct to say, in general terms, that the agreement 
of ideas is in all cases perceived. Extending Know- 
ledge, as Locke himself does, to include the evidence 
of the senses 11 , it is incorrect to say that, in all 
knowledge, we have a distinct consciousness of two 
ideas and their agreement. And the term Idea 
itself, used loosely by Locke, as by Descartes, for 
any object of consciousness, admits of a variety of 
subordinate senses, in some of which the definition 
is assuredly inaccurate. But, as limited to the 
logical judgment proper, as it has been above 
distinguished from the psychological, the definition 
is substantially correct, though susceptible of some 
verbal improvement. In every logical judgment 
there is a union of concepts ; and every concept is 
represented by a sign. The concepts themselves 
must be regarded as existing in the mind before 
their union ; and, the signs being practically fur- 
nished by the existing terms of a language, the 
logical judgment may be properly described as 
formed by the combination of concepts ; as its 

» Essay, B. IV. ch. 2. §. 14. 
F 



66 PROLEGOMENA LOGICA. 

representative, the proposition, is formed by the 
combination of terms. But to the judgments 
distinguished as psychological the definition of 
Locke is inapplicable, and here the objections of 
M. Cousin may be urged with full effect. Such 
are all the spontaneous judgments of the perceptive 
and imaginative faculties. Such too is the Cartesian 
cogito, ergo sum, a primitive judgment, not of the 
senses, but of the internal consciousness, which the 
opponents of Descartes, from Gassendi to Kant, 
have misrepresented as a logical reasoning from 
concepts °. The definition of Locke is therefore 
correct, as far as regards judgments of thought, 
properly so called; judgments formed by means of 
concepts, and, consequently, of language, and whose 
constituent parts are given piecemeal in words, and 
put together by the mind in the act of judging. It 
is incorrect, as regards all judgments, whether con- 
cerning the ego or the non-ego, which the mind 
forms for itself, by an immediate act of conscious- 
ness, without the aid of verbal or other signs of 
voluntary institution. 

From the definition of Locke, we proceed to 

° See an article in Cousin's Fragments Philosophiques, 
" Sur le vrai sens du cogito, ergo sum.'" To this lam indebted 
for the following quotation from Descartes himself, " Cum 
itaque quis advertit se cogitare, atque inde sequi se existere, 
quamvis forte nunquam antea qusesiverit quid sit cogitatio 
nee quid existentia, non potest tamen non utramque satis 
nosse, ut sibi in hac parte satisfaciat." Responsio ad sextas 
objectiones. 



PROLEGOMENA LOG1CA. 67 

consider that of Kant. In the Critical Philosophy, 
Thought and Judgment are synonymous and the 
act of the understanding. The understanding may 
be defined indifferently, the faculty of thinking, or 
the faculty of judging; for all thought is cognition 
by means of concepts ; and all concepts are the 
predicates of possible judgments, and are, by such 
judgments, referred to objects of sensible intuition, 
either immediately, or through the interposition of 
lower concepts p . The intuitions of sense being, 
according to Kant's theory of perception, im- 
mediate representations of objects, the judgment 
is thus the mediate cognition of an object, or the 
representation of a representation q . 

In a psychological point of view, the Kantian 
definition of Judgment is too narrow ; as it virtually 



p « vVir konnen alle Handlungen des Verstandes auf Ur- 
theile zuruckfuhren, so dass der Verstand iiberhaupt als ein 
Vermogen zu urtbeilen vorgestellt werden kann. Denn er 
ist nach dem Obigen ein Vermogen zu denken. Denken ist 
das Erkenntniss durch Begriffe. Begriffe aber beziehen sich, 
als Pradicate moglicher Urtheile, auf irgend eine Vorstellung 
von einem noch unbestimmten Gegenstande." Kritik der r. V. 
p. 70. Ed. Bosenkranz. 

i " Da keine Vorstellung unmittelbar auf den Gegenstand 
geht, als bios die Anscbauung, so wird ein Begriff niemals 
auf einen Gegenstand unmittelbar, sondern auf irgend eine 
andre Vorstellung von demselben (sie sey Anscbauung oder 
selbst scbon Begriff) bezogen. Das Urtbeil ist also die 
mittelbare Erkenntniss eines Gegenstandes, mithin die Vor- 
stellung einer Vorstellung desselben." Kritik der r. V. 
p. 69. 

f2 



68 PROLEGOMENA LOGICA. 

denies that any act of Judgment whatever is per- 
formed in the exercise of the intuitive faculties ; a 
denial which the author repeats still more explicitly 
in other passages r . In a logical point of view, it 
is too wide ; the province of Judgment being made 
coextensive with the whole of Thought, including, 
therefore, under it, Conception or Simple Appre- 
hension. Every concept, according to Kant, is the 
predicate of a possible judgment, in which it may 
be affirmed of any of the objects of intuition 
included within its sphere. He might have gone 
further, and said that, in all positive thinking, the 
possible judgment becomes an actual one. But it 
is a psychological, not a logical judgment. It 
affirms only the mental existence of the object, as 
now present in thought ; and the affirmation is neces- 
sarily true, whatever be the nature of the object. 
To make the doctrine of Kant consistent, the pro- 
vince assigned to Judgment must be either extended 
or contracted. It must either be extended, to de- 
note every consciousness of a relation between 
subject and object, i. e. to every operation of mind, 
or it must be contracted, to denote the conscious- 
ness of a relation between two objects of thought; 

r " Wahrheit oder Schein sind nicht im Gegenstande, 
so feme er angeschaut wird, sondern im Urtheile iiber den- 
selben, so feme er gedacht wird. Man kann also zwar 
richtig sagen : dass die Sinne nicht irren, aber nicht darum, 
weil sie jederzeit richtig urtheilen, sondern weil sie gar nicht 
urtheilen." Kritik der r. V. p. 238. 



PROLEGOMENA LOGICA. 69 

in which case it does not extend beyond the logical 
judgment by means of, at least, two concepts. 

Having thus pointed out the distinction of 
Thought from other mental acts, and its various 
subdivisions relatively to Logic, 1 shall proceed to 
offer a few observations on the nature of Law, in 
so far as that term is applicable to a conscious 
subject. 



CHAP. III. 

ON LAW, AS BELATED TO THOUGHT AND OTHER OBJECTS. 

The following passage from Archbishop Whately's 
Logic may serve as an appropriate introduction 
to this part of our subject. " What may be 
called a mathematical impossibility, is that which 
involves an absurdity and self-contradiction ; e. g. 
that two straight lines should inclose a space, is 
not only impossible but inconceivable, as it would 
be at variance with the definition of a straight 
line. And it should be observed, that inability to 
accomplish any thing which is, in this sense, im- 
possible, implies no limitation of power, and is 
compatible, even with omnipotence, in the fullest 
sense of the word. If it be proposed, e. g. to 
construct a triangle having one of its sides equal 
to the other two, or to find two numbers having 
the same ratio to each other as the side of a 
square and its diameter, it is not from a defect of 
power that we are precluded from solving such a 
problem as these ; since in fact the problem is 
in itself unmeaning and absurd : it is, in reality, 
nothing, that is required to be done \" 

a Whately's Logic, p. 353. (Sixth Edition.) 



PROLEGOMENA LOGICA. 71 

Substantially, perhaps, this is not far from the 
truth. But it may be stated in a more satisfactory 
form, by divesting it of a hypothesis, which, even 
if true, (and this we have no means of ascertain- 
ing,) may for the present purpose be dispensed 
with b . 

When any thing is said to be inconceivable, it 
is thereby acknowledged that the human mind is 
not altogether unrestricted in its operations. It is 
bounded, not only as regards the sphere of objects 
of which it is permitted to take cognisance, but 
also as regards the manner in which it is capable 
of thinking about objects within that sphere. In 
other words, there are laws under which the mind 
is compelled to think, and which it cannot trans- 
gress, otherwise than negatively, by ceasing to 
think at all. 

The existence, then, of laws of thought, is a 
fact of which our every-day consciousness assures 
us. Necessity, of whatsoever kind, implies a ne- 
cessary agent, that is, an agent acting under a law. 
If, then, any question can be proposed to the mind 
of man, which he feels himself compelled to decide 
in one way only, that compulsion is at once an 

b In venturing to criticise this note, one of the most 
valuable portions of the Archbishop's work, I beg to state, 
that it is to the wording only of the first part that my 
remarks are intended to apply. With the just and philo- 
sophical distinction laid down in the same place between the 
three senses of the word impossibility, I have only to express 
full concurrence. 



72 PROLEGOMENA LOGICA. 

evidence of the existence of laws which as a thinker 
he is compelled to obey. 

And this admission is all that is required for 
the solution of such difficulties as that suggested 
above. If our whole thinking is subject to certain 
laws, it follows that we cannot think of any object, 
not even of Omnipotence itself, except as those 
laws compel us. The limitation does not lie in 
the object of which we think, but in the thinking 
subject. " Whatsoever we imagine," says Hobbes, 
* is finite. Therefore there is no idea or con- 
ception of any thing we call infinite. No man can 
have in his mind an image of infinite magnitude ; 
nor conceive infinite swiftness, infinite time, or 
infinite force, or infinite power. When we say any 
thing is infinite, we signify only, that we are not 
able to conceive the ends and bounds of the things 
named ; having no conception of the thing, but of 
our own inability ." 

It may be, indeed, that the conditions of possible 
thought correspond to conditions of possible being, 
that what is to us inconceivable is in itself non- 
existent d . But of this, from the nature of the 
case, it is impossible to have any evidence. If 



c Leviathan, i. 3. (p. 17. ed. Molesworth.) 

d In itself, distinguished from, as an object of thought. As 
the latter, it is of course impossible. The distinction between 
things per se, and things as objects of thought, will be 
familiar to every reader of Kant: it is, in fact, the cardinal 
point of the whole Critical Philosophy. 



PROLEGOMENA LOGICA, 



73 



man as a thinker is subject to necessary laws, he 
cannot examine the absolute validity of the laws 
themselves, except by assuming the whole question 
at issue. For such examination must itself be 
conducted in subordination to the same conditions. 
Whatever weakness, therefore, there may be in the 
object of criticism, the same must necessarily affect 
the critical process itself. 

We may indeed believe, and ought to believe, 
that the powers which our Creator has bestowed 
upon us are not given as the instruments of 
deception. We may believe, and ought to believe, 
that, intellectually no less than morally, the pre- 
sent life is a state of discipline and preparation for 
another; and that the portion of knowledge which 
our limited faculties are permitted to attain to 
here may indeed, in the eyes of a higher Intel- 
ligence, be but partial truth, but cannot be absolute 
falsehood. But in believing thus, we desert the 
evidence of Reason to rest on that of Faith, and 
of the principles on which Reason itself depends 
it is obviously impossible to have any other 
guarantee. 

But such a faith, however well founded, has but 
a regulative and practical, not a speculative appli- 
cation. It bids us rest content within the limits 
which have been assigned to us : it cannot enable 
us to overleap them, or to exalt to a more abso- 
lute character the conclusions obtained by finite 



74 PROLEGOMENA LOGICA. 

thinkers concerning finite objects of thought 6 . 
For the same condition which disqualifies us from 
criticising the laws of thought must also deprive 
us of the power of ascertaining how much of the 
results of those laws is true in itself, and how 
much is relative and dependent upon the parti- 
cular bodily or mental constitution of man during 
the present life. To determine this question, it 
would be necessary to examine the same con- 
clusions with a new set of faculties f and under 
new conditions of thought, so as to separate what 
is merely relative to the existing state of human 
consciousness, from what is absolute and common 
to other intelligences g . 

e When Kant [Kritik der r. V. p. 49.) declares that the objects 
of our intuition are not in themselves as they appear to us, he 
falls into the opposite extreme to that which he is combating: 
the Critic becomes a Dogmatist in negation. To warrant 
this conclusion, we must previously have compared things as 
they are with things as they seem ; a comparison w r hich is, ex 
hypothesi, impossible. We can only say, that we have no 
means of determining whether they agree or not. And, in the 
absence of proof on either side, the presumption is in favour 
of what is at least subjectively true. The onus probandi lies 
with the assailant, not with the defender, of our faculties. 
Cf. Eoyer-Collard, JourTroy's Eeid, vol. iv. p. 412. 

f See Eeid, Intell. Powers, Essay vi. ch. 5. (p. 447. ed. 
Hamilton.) 

s Truth relative to no intelligence is a contradiction in 
terms, as it implies a relation existing after one of the cor- 
relatives has been annihilated. Our only possible notion of 
absolute truth, is a truth relative to all intelligences. If all 



PROLEGOMENA LOGICA. 75 

In accordance with these views, we are natu- 
rally led to regard all the hitherto unsolved pro- 
blems of Metaphysics, as requiring to be treated 
from a psychological, instead of an ontological 
point of view. Instead of asking what are the 
circumstances in the constitution of things, by 
virtue of which they present such and such diffi- 
culties and contradictions to human understanding, 
we must ask what are the circumstances of the 
human understanding itself, by virtue of which a 
distinction exists between the conceivable and the 
inconceivable. Such, in fact, was the revolution 
introduced by Kant into metaphysical speculation ; 
a revolution which he aptly compares to that 
effected in Astronomy by Copernicus, when he 
thought of investigating the apparent motion of 
the heavens from the side of the spectator, instead 
of from that of the objects. The advantages of 
such a treatment are obvious. From the objective 
view, we obtain only the fact, that certain questions 
have up to the present time remained unsolved. 



truth is subjective which implies a cognitive power, Omni- 
science itself has but subjective truth. "Aux termes de la 
philosophic de Kant," says M. Cousin, " la raison divine 
serait done aussi frappee de subjectivite, par cela meme que 
cette raison reside dans un sujet determine qui est Dieu." 
(Lecons sur Kant, p. 850.) Within the limits of human 
knowledge the same principle is allowed by Kant himself, 
" so bedeutet die objective Giiltigkeit des Erfahrungsurtheils 
nichts anders, als die nothwendige Allgemeingiiltigkeit des- 
selben." Prolegomena, §. 18. 



76 PROLEGOMENA LOGICA. 

From the subjective view, we learn why they are 
insoluble ; and the answer to this question deter- 
mines the laws and limits of thought. The abuse 
of the method appears in the attempts of the suc- 
cessors of Kant, especially of Schelling and Hegel, 
to construct a philosophy of the absolute from the 
subjective side, by denying in certain relations the 
validity of those laws of thought which they 
acknowledge in others, and endeavouring thereby 
to do away with relation in consciousness alto- 
gether. Such a system, with whatever ability it 
may be constructed, carries in its fundamental 
conception the germ of its own refutation. It 
commences by giving the lie to consciousness ; it 
proceeds by dividing the human mind against 
itself, the understanding against the reason, and 
the reason against the understanding ; it ends by 
leaving no test by which its own truth can be 
determined. But the philosophy of Kant is like 
the spear of Achilles, and possesses virtue to heal 
the wounds which it has itself inflicted. While it 
is impossible to deny the lineal descent of the 
philosophy of Schelling and of Hegel from a one- 
sided view of Kantian principles, it is equally clear, 
that the only satisfactory refutation of the extra- 
vagances of that philosophy must be based on a 
sober acknowledgment of those laws and limits of 
the mental faculties which Kant has been mainly 
instrumental in pointing out. 

We must admit, then, that our present faculties 



PROLEGOMENA LOGICA. 77 

are trustworthy guides to that portion of know- 
ledge which God designs us to attain to in our 
present state ; that the laws to which these faculties 
are subjected, though perhaps not absolutely bind- 
ing on things in themselves, are binding upon our 
mode of contemplating them ; that, while we obey 
these laws, we seek after truth, according to our 
kind and in conformity with the end of our intel- 
lectual being ; and that, when we neglect them, 
we abandon ourselves to every form of error ; or 
rather, we lose all power of discerning between 
error and truth ; we commence by an act of intel- 
lectual suicide, and construct a system which, by 
virtue of its fundamental principle, must disclaim 
all superiority over, and decline to combat with, 
any rival theory ; its sole claim to attention being, 
that it may, for aught we know, be true, or false, or 
both, or neither. 

To apply these principles to the question with 
which we commenced. Among the limitations to 
which even Omnipotence is regarded as subject, 
none is of older birth, or has been more frequently 
alleged, than the impossibility of undoing an act 
already done, 

povov yoiq avTOv xct) 0eo£ crTegia-xsTai, 

Now it may be that Time and Space are, as Kant 
maintains, merely subjective conditions of human 
sensibility. As such, they limit the whole exercise 
of human thought. But the limits of the thinking 



78 PROLEGOMENA LOGICA. 

faculty are limits of things as objects of thought 
only ; and beyond that sphere we know nothing. 
It may be that the whole distinction of past, 
present, and future, has no place relatively to other 
intelligences than ours. Still, that distinction con- 
tinues to influence all human thought ; and every 
act, as an object of thought, must be regarded as 
taking place according to the conditions of temporal 
succession. If we cease to regard it in this light, 
we do not extend our knowledge, but abandon the 
problem as (humanly speaking) unthinkable. The 
limitation, then, is not of Omnipotence in itself, but 
of all power as the object of human thought \ The 
ultimate consequence of this admission will be, that 
the unlimited is not an object of human thought 
at all 1 . It may be an object of human belief, but 
the two provinces are not coextensive. 

So again with reference to the impossibility of 
reversing a necessary truth, such as those of 
Geometry. To whom is the problem, to construct 
a triangle, one of whose sides shall be greater than 

h This distinction is drawn by Locke in his Second Keply 
to the Bishop of Worcester. " But it is further urged, that 
we cannot conceive how matter can think. I grant it : but to 
argue from thence, that God therefore cannot give to matter 
a faculty of thinking, is to say God's omnipotency is limited 
to a narrow compass, because man's understanding is so ; 
and brings down God's infinite power to the size of our 
capacities." 

* See the admirable Article on M. Cousin's Philosophy by 
Sir W. Hamilton, Edinburgh Review, No. 99, p. 203. 



J 



PROLEGOMENA LOGICA. 79 

the other two, " unmeaning ?" Clearly to the 
Geometer, whose science has already shewn him 
the necessary truth of a contradictory proposition. 
By a law of thought, he is compelled to deny that 
two contradictory assertions can be true at the 
same time. Why they may not both be true at 
different times, why a mathematical proposition 
once demonstrated is held always and every where 
true, and its contradictory always and every where 
false ; while other truths, however certain at present, 
are allowed only to a limited extent under tem- 
poral or local restrictions, requires some further 
consideration. 

Necessity is the result of law, and law implies 
an agent whose working is regulated thereby \ 
But it is a law only to that which works under 
it : to an observer, who sees the results of the law 
without being subject to its influence, it is no more 
than a fact evidenced by or inferred from sensible 
observation, and can never obtain higher value 
than that of a generalization from a more or less 
extended experience. Hence arise two very dif- 
ferent kinds of necessity, the results respectively of 
laws of the ego and of the non-ego 1 ; of laws under 

k " All things that are, have some operation not violent or 
casual. . . . That which doth assign unto each thing the kind, 
that which doth moderate the force and power, that which 
doth appoint the form and measure, of working, the same we 
term a Law." Hooker, E. P. i. 2. 

1 It is much to be wished that these expressions, or some 
equivalent, were more naturalized in English philosophy. In 



80 PROLEGOMENA LOGICA. 

which I feel myself compelled to think, and of 
laws under which I see other agents invariably 
working. These two, it is essential to all sound 
thinking to distinguish from each other ; and the 
more so, inasmuch as they have been perpetually 
confounded together; the distinctive features of each 
have been overlooked by the disciples of opposite 
schools ; by one party, laws of thought have been 
degraded to generalizations from experience ; by 
another, empirical laws have been invested with 
the character and authority of original principles 
of mind m . And yet, apart from the psychological 
tenets of any particular school, it would seem as 
if a distinctive criterion might a priori be deter- 
mined, from a mere analysis of the notion of law 
and its operation. 

Setting aside, for an instant, the question, how 
the mind of man is actually constituted, let us 
suppose an intelligent being, subject to laws under 
which he is compelled to think, and placed in the 
midst of a world of material agents, subject to laws 
under which they must act. What would be the 
distinctive character presented to his mind by these 

Germany and France they are fully established as technical 
terms, and the foundation of the most important distinctions 
in mental science. In adopting here the Latin expressions 
instead of English equivalents, I have been guided by the 
authority of Sir W Hamilton, Reid's Works, p. 100. 

m The opposite theories of Dr. Whewell and of Mr. Mill, 
on the nature of axiomatic principles, exhibit the extreme 
views in a remarkable degree. See Appendix, note A. 



PROLEGOMENA LOGICA. 81 

respective laws of himself and of the world without ? 
The laws of the planetary motions are absolutely 
binding on the moving bodies themselves, inde- 
pendently of the existence of astronomical science. 
But it is optional with an intelligent being to study 
astronomy or not; and, when he does so, he observes, 
as matter of fact, how such laws influence their own 
subordinate agents ; but he does not himself become 
an agent under their influence. As facts of his 
experience 11 , they are known solely in and through 
his observation ; as laws within their own sphere, 
they are independent of his knowing aught about 
them. But the laws of his mind came into opera- 
tion as laws when the act of thinking commences, 
and are binding, not on this or that class of phy- 
sical phenomena, but upon the thinker himself in 
the contemplation of all of them. Hence it is not 
optional with him whether he will think according 
to these or other conditions : choose what object 
of study he will, he cannot think at all, he cannot 
conceive his liberty of choosing, without being ipso 
facto under their influence. Hence arises an 
obvious criterion. A law which is not binding upon 
me as a thinker may at any time be reversed, 
without affecting my mode of observing the same 

n Les verites primitives sont de deux sortes, comme les 
derivatives. Elles sont du nombre des verites de raison, ou 
des verites de fait. Les verites de raison sont necessaires, 
et celles de fait sont contingentes." Leibnitz, Nouv. Essais, 
iv. 2. 

G 



82 PROLEGOMENA LOGICA. 

agents under their new conditions. And I have 
no difficulty in conceiving such a reversal as at 
any moment possible, because, antecedent to ex- 
perience, I had no internal bias which required the 
recognition of the existing law rather than of any 
other. I have only to discard an adventitious 
knowledge. But the reversal of a necessary law 
of thought, supposing that there are such, is, from 
the nature of the case, inconceivable ; for concep- 
tion is itself the servant of the law, and, ex hypothesi, 
cannot rebel against it. I cannot, by an act ot 
thought, annihilate the conditions by which all 
thought is governed. I can, indeed, admit the pos- 
sibility that there may be other beings thinking 
under other laws ; but I can form no positive con- 
ception of their nature. Such a supposition is 
not thought, but its negation. A mind cannot 
think by other laws than its own. 

Now how far is this hypothesis supported by 
facts ? Is it a matter of fact, that men are ac- 
quainted with certain truths which they acknow- 
ledge to be necessary only while the present laws 
of nature remain in force, and which they can 
conceive as reversable at any moment, and others 
which they are compelled to regard as necessary 
under all circumstances of which they are capable of 
thinking ? Is it a matter of fact, that men do not 
attribute the same necessity and universality to 
physical as to mathematical truths ? Do they not 
acknowledge that, while the laws of the physical 



PROLEGOMENA LOGICA. 83 

world continue as they are, seed-time and harvest, 
and cold and heat, and summer and winter, and 
day and night shall never cease ; and yet, have 
they any difficulty in conceiving the earth's rota- 
tion stopped by some superior power, and one half 
of the globe left from that time forth in perpetual 
day-light ° ? Or do they see the least improbability, 
not to say impossibility, in the supposition, that in 
some remote part of space there may exist worlds in 
which the alternations of the seasons have no place ? 
On the other hand, can they conceive the same power 
forming a triangle with more or less than two 
right angles? can they conceive an occurrence 
taking place in any portion of space without a cause ? 
or an object possessing neither of two contradictory 
attributes ? If such a distinction exists, and our 



" Tous les exemples qui confirment une verite generale, 
de quelque nombre qu'ils soient, ne suffisent pas pour etablir 
la necessite universelle de cette meme verite : car il ne suit 
pas, que ce qui est arrive arrivera to uj ours de meme. Par 
exemple, les Grecs et les Eomains et tous les autres peuples 
ont toujours remarque, qu'avant le decours de vingt quatre 
heures le jour se change en nuit, et la nuit en jour. Mais on 
se seroit trompe si Ton avoit cru, que la meme regie s'observe 
partout, puisqu'on a vu le contraire dans le sejour de Nova 
Zembla. Et celui-la se tromperoit encore, qui croiroit, que 
c'est au moins dans nos climats une verite necessaire et 
eternelle, puisqu'on doit juger, que la Terre et le Soleil meme 
n'existent pas necessairement, et qu'il y aura peut-etre un 
terns, ou ce bel astre ne sera plus avec tout son Systeme, au 
moins en sa presente forme." Leibnitz, Nouveaux Essais, 
Avant-Propos. 

g2 



84 PROLEGOMENA LOGICA. 

daily consciousness assures us that it does, the fact 
at once affords at least a strong presumption, that 
the necessity in the one case is a necessity of 
observation only, depending on the laws of the 
world without, in the other a necessity of thought, 
depending on the laws of our mental constitution. 
But granting that Thought has its laws, how are 
these to he discovered ? Only by reflection upon 
the phenomena of actual thinking and the restric- 
tions to which, in all cases, we experience it to be 
subject. To learn how we think, we must in the 
first place actually think ; and a multitude of suc- 
cessive acts of thought will be necessary, before we 
become aware that certain conditions are con- 
tingent and limited to some of those acts only, 
while others are necessary and cannot but be 
present in all p . If, therefore, Experience be taken 
in a wide sense, as coextensive with the whole of 
consciousness, to include ail of which the mind is 
conscious as agent or patient, all that it does from 
within, as well as all that it suffers from without, — 
in this sense, the laws of thought as well as the 
phenomena of matter, in fact, all knowledge what- 
ever, may be said to be derived from experience q . 

p See Hamilton on Eeid, p. 772. and Cousin, Cours de Philo- 
sophic, Lee. 22. 

i In this extended sense, Wolf derives the principle of con- 
tradiction from experience : " Exjoeriri dicimur, quicquid ad 
perceptiones nostras attenti cognoscimus. Solem lucere cog- 
noscimus ad ea attenti, quae visu percipimus. Similiter ad 
nosmet ipsos attenti cognoscimus, nos non posse assensum 



PROLEGOMENA LOGICA. 85 

But further, experience in its narrower and more 
common meaning, as limited to the results of sens- 
ation and perception only 1 , is, though not the 
source, the indispensable conditio?! of discovering 
the laws of mind as well as of matter. For, to 
think actually, we must think about something ; 
this something, the object-matter of thought, what- 
ever it may be, must in the first instance be sup- 
plied through the medium of the senses ; for thought 
itself does not become an object of thought till 
after it has been called into exercise by objects 
presented from without s . But while the material 
or external element varies with every successive 
act of thought, the formal or internal remains the 
same in all; and thus the necessary law, binding on 
the thinker in every instance, is distinguished from 
the contingent objects, about which he thinks on 
this or that occasion. 

This last consideration necessitates a further 
division of those truths, which have already been 
distinguished as necessary, and therefore not de- 
rived from experience. While we maintain that 
all necessary truths must have their origin in the 

prsebere contradictoriis, v. gr. non posse sumere tanquam 
verum, quod simul pluat vel non pluat." Ph. Rat. §. 664. 
Here it should be observed that perception is used in a wider 
sense than that to which Eeid and the Scottish Philosophers 
after him restrict it. 

r 'Ek fxev ovv aladrj(Tea>s •yiVerai fivrjur], €K de (JLvrjfirjs TroXkaKts tov 
avrov yiuofievrjs e [jltt etpia. Arist. Anal. Post. ii. 19. 
s Cf. Arist. De Anima, iii. 4. 7. 



86 PROLEGOMENA LOGICA. 

constitution of the mind itself, and are virtually 
prior to all experience, they cannot all of them be 
referred to Laws of Thought properly so called. 
For thought, as thought, cannot be limited to 
any special class of objects : its laws must operate 
in all cases alike, whatever be the matter on which 
it is engaged. That every triangle has its angles 
equal to two right angles, is indeed a necessary 
truth; but it is true of triangles only, and cannot 
be applied to any other object. But that the 
same subject cannot possess contradictory attri- 
butes, is a principle equally applicable to the 
objects of geometrical demonstration and to the 
most contingent facts of sensible experience. It 
is equally certain, that no man can at once be 
standing and not standing, as that the angles of a 
triangle cannot be both equal and unequal to two 
right angles. Hence the criterion of absolute 
necessity, though valid as far as it goes, is not 
adequate to determine the whole question. It 
serves to distinguish judgments a priori from 
judgments of experience : it does not distinguish 
between different classes of the former, nor explain 
their several relations to the mind, which is the 
common source of all. Of the various judgments 
which have been enumerated by philosophers as 
necessary truths, it will be sufficient for our present 
purpose to select three classes, which may be 
severally distinguished as Mathematical, Meta- 
physical, and Logical Necessity. All these, being 



PROLEGOMENA LOGICA. 87 

in different ways regarded as absolutely and 
universally necessary, must be considered as in 
different ways dependent on laws of our mental 
constitution. From all, must be distinguished what 
is commonly called Physical Necessity, or belief 
in the permanence of Laws of Nature. The 
several distinctions may be represented by the 
following questions. 

I. Why do I judge, that a triangle can under 
no circumstances whatever have more or less than 
two right angles ? 

II. Why do I judge, that every sensible quality 
must belong to some subject, and that every 
change is and must be brought about by some 
cause ? 

III. Why do I judge, that two contradictory 
attributes can under no circumstances whatever 
coexist in the same subject ? 

IV. Why do I judge, that the alternations of 
day and night will not, under the existing circum- 
stances of our globe, cease to take place ? 

The last of these obviously stands on a different 
ground from the other three. I am immediately 
cognisant of law only as I am conscious of its 
obligation upon myself. The law itself may be 
physical, intellectual, or moral ; but to know it as 
a law, I must know it as a condition which I 
cannot or ought not to transgress. Law, in this 
sense, as a discerned obligation, can obviously 
exist only in relation to a conscious agent ; and 



88 PROLEGOMENA LOGICA. 

even with regard to conscious agents, other than 
myself, I only infer the existence of the law from 
a supposed similarity between their constitutions 
and my own. But, as regards unconscious agents, 
Law means no more than a constantly observed 
fact in its highest generalization. When I speak 
of the alternations of day and night as consequent 
on a law of nature, I mean no more than that the 
alternation has invariably been observed to take 
place : and, when I resolve such alternations into 
the law of the earth's rotation, I mean only that 
the earth does constantly revolve on her axis once 
in twenty-four hours. Or, if I could resolve all 
the phenomena of the material world into an 
universal law of gravitation, I should obtain no 
more than the universal fact, that all particles of 
matter in the universe do gravitate towards each 
other, and that certain subordinate combinations 
of those particles present certain phenomena in so 
doing. But I have not, by this resolution, got any 
nearer to necessity ; for the gravitation of bodies 
in the inverse ratio of the square of the distance 
is, like the ebb and flow of the tides, or the 
elliptical orbits of the planets, an observed fact 
in the order of nature, and it is no more*. My 
belief in the continuance of this observed order 
may perhaps be explained by some law of my 
mental constitution ; but, as thus explained, it is a 
law of mind, and not of matter. Under what 
* See Stewart, Elements, vol. ii. ch. 2. sect. 4. 



PROLEGOMENA LOGICA. 89 

circumstances certain facts of nature may be 
resolved into others, and what kinds of experiment 
and observation will contribute to this end, are 
questions which, with all their importance, are 
totally distinct from those which form the object 
of the present inquiry. 

I shall only observe here, that to call such 
questions a portion of Logic, that is, to regard the 
New Organon as a supplement to the Old, and 
both as forming parts of the same Science, is to 
confound two essentially distinct branches of 
knowledge, distinct in their end, in their means, 
and in their evidence 11 . "We do not enlarge the 
sciences," says Kant, " but disfigure them, when 
we suffer their boundaries to run into one another." 
The confusion produced in the present instance 
is perhaps the most injurious of all to sound 
thinking, a confusion between the mental self and 
its sensible objects, the ego and the non-ego, the 
positive and negative poles of speculative philo- 
sophy. 

u On this distinction some excellent remarks will be found 
in M. Jouffroy's Preface to his translation of Keid, p. 43. 



CHAP. IV. 

ON THE PSYCHOLOGICAL CHAEACTEE OF MATHEMATICAL NECESSITY. 

It has been already observed, that whatever 
truths we are compelled to admit, as every where 
and at all times necessary, must have their origin, 
not without, in the laws of the sensible world, but 
within, in the constitution of the mind itself a . 
Sundry attempts have, indeed, been made to derive 
them from sensible experience and constant asso- 
ciation of ideas b ; but this explanation is refuted 
by a criterion decisive of the fate of all hypotheses ; 
it does not account for the phenomena. It does 
not account for the fact, that other associations, 
as frequent and as uniform, are incapable of pro- 
ducing a higher conviction than that of a relative 

a " La preuve originaire des verites necessaires vient du 
seul entendement, et les autres verites viennent des expe- 
riences ou des observations des sens. Notre esprit est 
capable de connoitre les unes et les autres, mais il est la 
source des premieres, et quelque nombre d'experiences parti- 
culieres qu'on puisse avoir d'une verite universelle, on ne 
sauroit s'en assurer pour to uj ours par 1 'induction, sans en 
connoitre la necessite par la raison." Leibnitz, Nouv. Essais, 
1. i. ch. 1. 

b See, for example, Mill's Logic, vol. i. p. 305. 



J 



PROLEGOMENA LOGICA. 91 

and physical necessity only. And, indeed, this 
might have been expected beforehand : for the 
utmost rigour in a law of the sensible world may 
furnish a sufficient reason why phenomena must 
take place in a certain manner, but furnishes no 
reason at all why I must think so. 

But it is one thing to recognise the operation 
of a mental law, and another to discover the law 
itself. The distinction above noticed between 
Mathematical, Metaphysical, and Logical Neces- 
sity, implies, that, although the origin of all is to 
be sought for in the mind itself, they are in some 
way differently related to one or other of the 
special faculties of their common source. We 
must further inquire, what is the peculiar relation 
of the mind to mathematical ideas c , by virtue of 
which, not merely the general laws of all thinking, 
but the special applications of those laws in Arith- 
metic and Geometry, possess a necessity which is 
not found when they are applied to concepts 
generalized from experience. How is it that in 
some reasonings both matter and form can be 
furnished by the mind itself, while in others the 
form alone is from the mind, the matter being 
derived from experience ? 

Before entering upon this question, it will be 

c The word idea is here used intentionally, as, in modern 
philosophy, the most vague and indeterminate that could be 
selected. It would be an anticipation of what has yet to be 
determined to give any more definite expression. 



) 



92 PROLEGOMENA LOGICA. 

necessary to give some account of Kant's cele- 
brated distinction between Analytical and Syn- 
thetical Judgments. An Analytical or Explicative 
Judgment contains nothing in the predicate but 
what has been already implied in the conception 
of the subject. For example : since the con- 
ception of body implies extension, the proposition, 
fC all bodies are extended," is an Analytical Judg- 
ment. Of this character are all propositions in 
which, in scholastic language, the predicate is said 
to be of the essence of the subject; whether a part 
.(j of the essence, as in the predication of genus or 

differentia, or the sum of the parts, as in a 
definition 3 . In a Synthetical or Ampliative Judg- 
ment, on the other hand, the predicate adds an 
attribute to the subject which has not been already 
thought therein. Thus the proposition, " all bodies 
are heavy," is a Synthetical Judgment, the attribute 
heavy not being thought in the mere conception 
of body. Of this kind are all propositions in which 
the predicate is said to be joined to the essence of 
the subject, as a property or accident 6 . 

All Analytical Judgments are formed by the mind 
a priori, whether the notion analysed be empirical 
or not. For the mind, having once gained this 
notion as a subject, has no occasion for any addi- 
tional experience to determine the predicate which 

d The substitution of definition for species is intentional. 
e See Kant, Kritik der r. V. p. 21. Prolegomena, p. 16. 
ed. Rosenkranz. 



PROLEGOMENA LOGICA. 93 

is already given therein f . Any Science whatever 
may therefore have abundance of necessary truths 
of this kind : but such do not contribute in any 
way to the extension of our knowledge, but only 
to the more distinct consciousness of what we 
already possess. A Synthetical Judgment, on the 
other hand, is a positive extension of our know- 
ledge, but requires for its formation something 
more than the concept which stands as its subject. 
All empirical judgments are synthetical g : but 
mathematical necessity requires that the mind 
should be able to form for itself synthetical judg- 
ments not dependent on experience. 

The axioms of Geometry contain specimens of 
both kinds of judgment, Those which relate ex- 
clusively to geometrical objects, such as, " a straight 
line is the shortest distance between two points h ," 
" two straight lines cannot enclose a space," " two 
straight lines which, being met by a third, make the 
interior angles less than two right angles, will meet 
if produced," have been shewn by Kant to be syn- 
thetical 1 ; and it is with reference to these that he 

f Kant, Proleg. p. 17. 

s Kant, Kritik der r. V. p. 700. Proleg. p. 18. 

h This is sometimes given as a definition, but it is properly 
synthetical. 

1 " Dies sind die Axiome, welch e eigentlich nur Grossen als 
solchebetreffen." Kant, Kritik der r. F.p.l43.cf.p.703. &c. Proleg. 
p. 20. Hence the error of Leibnitz, in maintaining that all 
axioms (excepting, of course, identical judgments themselves) 
may be demonstrated from definitions and the judgments of 



94 PROLEGOMENA LOGICA. 

discusses the well-known question, how are synthe- 
tical judgments a priori possible ? But those axioms 
which are not peculiar to Geometry, the common 
principles of Aristotle k , such as, "the whole is greater 
than its part/' " things that are equal to the same 
are equal to each other," " if equals be added to 
equals, the sums are equal," are analytical 1 . The 
two last, indeed, may be easily shewn to be merely 
various statements of the Principle of Identity, 
" Every thing is equal to itself," or, ei A = A." 
Thus, if the common magnitude of the first pair 
of equals be represented by A, and that of the 
second by B, the axiom, " if equals be added to 
equals, the sums are equal," is expressed in the 
identical judgment, "A + B = A + B". m 

identity. (Opera, Erdm. p. 81.) He selects, as a specimen, the 
analytical judgment, " the whole is greater than its part," and 
of such his theory is correct ; but no synthetical judgment 
can be proved solely from analytical premises ; and, without 
synthetical axioms, Geometry is impossible. 

k Synthetical axioms are not included, as they should have 
been, under the peculiar principles (iStat apx a <) of Aristotle, which 
are divided into definitions and hypotheses. With the excep- 
tion of this omission, Aristotle's account of geometrical demon- 
stration is far more accurate than any that can be found in 
modern philosophy before Kant. 

1 Cf. Kant, Kritik der r. V. p. 143. 

m Dr. Whewell, Phil. Ind. Sc. vol. i. p. 134. speaks of this 
axiom as a condition of the intuition of magnitudes. This is 
a confusion of the common axioms of Logic with the peculiar 
axioms of Geometry. Stewart, Elements, vol. ii. ch. i. falls 
into the opposite error, regarding all the truths of geometry 
as deduced from definitions. 



PROLEGOMENA LOGICA. 95 

The former class of axioms determine the pecu- 
liar character of all the conclusions of Geometry : 
the latter have no peculiar relation to Mathematics, 
but depend on the general conditions of all think- 
ing whatever, and have therefore a logical, not a 
mathematical necessity. The whole question of 
the superior necessity of Geometry to Physical 
Science depends upon the manner in which we 
account for the origin of the synthetical axioms 
relating to magnitudes as such. As an instance, 
we may take the proposition, " Two straight lines 
cannot enclose a space." 

An eminent writer of the present day has laboured 
hard to prove that this principle is nothing but a 
generalization from experience, and, consequently, 
that our belief in the superior necessity of mathe- 
matical as compared with physical truths is a mere 
self-deception. He lays much stress on one of 
the characteristic properties of geometrical forms, 
their capacity of being painted in the imagination 
with a distinctness equal to reality : in other words, 
the exact resemblance of our ideas of form to the 
sensations which suggest them n . But while it is 
impossible to deny the ability with which Mr. Mill 
combats the notion of an a priori necessity in 
Mathematics, it is impossible to assent to an argu- 
ment which contradicts the direct evidence of 
consciousness. Nor does his reasoning against 
Dr. Whewell, however powerful as an argumentum 
n Mill's Logic, vol. i. p. 309. 



96 PROLEGOMENA LOG1CA. 

ad hominem, meet the real question at issue. What 
is required is to account, not for the necessity of 
geometrical axioms as truths relating to objects 
without the mind, but as thoughts relating to objects 
within. Mathematical judgments are true of real 
objects only hypothetically. If there exist any 
where in the world a pair of perfect straight lines, 
those lines cannot enclose a space. But if such 
lines exist no where but in my imagination, it is 
equally the case that I cannot think of them as 
invested with the contrary attribute. That which 
is to be accounted for is, not the physical fact that 
certain visible objects possess certain properties, 
but the psychological fact that, in the case of 
geometrical magnitudes, I am compelled to invest 
imagined objects with attributes not gained by 
mere analysis of the notion under which they are 
thought; — a compulsion of which I am not conscious 
with regard to the most uniform associations of 
phenomena within the field of sensible experience. 
A sensible object may have been familiar to me from 
childhood ; but, suppose the external reality de- 
stroyed, I can assert nothing with certainty of its 
imaginary representative, except what is contained 
in the concept itself. So long as I have to conform 
my judgments, not to the actual laws of the exist- 
ing course of nature, but to the possible conditions 
of an imaginary state of things, I have no difficulty 
in attributing contradictory attributes successively 
to the same object. I may imagine the sun rising 



PROLEGOMENA LOGICA. 97 

and setting as now for 100 years, and afterwards 
remaining continually fixed in the meridian. Yet 
my experience of the alternations of day and night 
has been at least as invariable as of the geo- 
metrical properties of bodies. I can imagine the 
same stone sinking 99 times in the water, and 
floating the 100th; but my experience invariably 
repeats the former phenomenon only. Whereas, in 
the case of two straight lines, which, so far as they 
are objects of experience, stand only on a level with 
the above and similar instances, the mind finds 
itself compelled to assert as necessary one attribute, 
not contained in the concept, and to reject its con- 
tradictory as impossible. 

The possibility of forming synthetical judgments 
a priori in Geometry admits of only one adequate 
explanation : viz. that the presentative intuition, as 
well as the representative notion, is derived from 
within, not from without : in other words, that 
both the matter and form of the judgment are 
determined subjectively. If it can be shewn that 
the object of which pure Geometry treats is not 
dependent on sensibility, but sensibility on it ; that 
it is a condition under which alone sensible 
experience is possible, it is obvious that its charac- 
teristics must accompany all our thoughts con- 
cerning any possible object of such experience; 
that its laws must be equally binding upon the 
imaginary representation as upon the sensible 
percept ; for, abstract as we may from this or that 

H 



98 PROLEGOMENA LOGICA. 

particular phenomenon of experience, we are clearly 
incompetent to deprive it of those conditions under 
which alone experience itself is possible. 

Such a condition is furnished to us by the intui- 
tion of Space. That this is a subjective condition 
of all sensible perception, and not a mere empirical 
generalization from a special class of phenomena, 
is evident from the fact, that it is impossible, by any 
effort of thought, to contemplate sensible objects, 
save under this condition. We may shift our atten- 
tion at will from this object to that ; but we can 
think of none, save as existing in space. We may 
conceive the whole world of sensible phenomena 
to be annihilated by the flat of Omnipotence ; but 
the annihilation of space itself is beyond the power 
of thought to contemplate. That things in them- 
selves must exist in space, and, as such, must be so 
presented to every possible intelligence, is more 
than we may venture to affirm ; but this much is 
certain, that man, by a law of his nature, is com- 
pelled to perceive and to think of them as so 
existing. 

Upon this law of the mind depends the certainty 
of Geometrical axioms, as thoughts, though not as 
truths. The peculiar figures of space must, indeed, 
be originally suggested empirically, from observ- 
ation of the actual figures of body; but this expe- 
rience is still subject to the same condition. Bodies 
cannot be perceived or imagined, but in space : 
bodies of this or that figure cannot be perceived or 



PROLEGOMENA LOGICA. 9,9 

imagined, but as occupying a similarly figured 
space. The modifications originally suggested by 
the former become an object of thought as 
existing in the latter ; and the features exhibited 
now and here in the one, we are compelled to 
think as existing always and every where in the 
other. 

The sensationalist is, therefore, in a certain sense 
right, in deriving geometrical axioms from expe- 
rience. It must be conceded to him that, had 
we never seen two straight lines, had we never 
observed that as a matter of fact they did not in 
that particular instance enclose a space, we should 
never have arrived at the conviction that they 
cannot do so in any instance. But this is equally 
true of any product of the imagination. If I had 
never seen separately the upper parts of a man 
and the lower parts of a horse, I could not unite 
them together in the fantastic image of a centaur. 
If I had never seen any black object, I could not 
combine that colour with a known form, so as to 
produce the imagination of a black swan. But 
why is it, that in the one case I find no difficulty 
whatever in going beyond or against the whole 
testimony of my past experience, while in the 
other such transgression is altogether out of my 
power ? Experience has uniformly presented to 
me a horse's body in conjunction with a horse's 
head, and a man's head with a man's body ; just 
as experience has uniformly presented to me space 

h2 



100 PROLEGOMENA LOGICA. 

enclosed within a pair of curved lines, and not 
within a pair of straight ones. Why do I, in the 
former case, consider the results of my experience 
as contingent only and transgressible, confined to 
the actual phenomena of a limited field, and 
possessing no value beyond it; while, in the latter, 
I am compelled to regard them as necessary and 
universal ? Why can I give in imagination to a 
quadruped body what experience assures me is 
possessed by bipeds only ? And why can I not, 
in like manner, invest straight lines with an attri- 
bute which experience has uniformly presented in 
curves ? 

Can it be said that the ideas in the latter case 
are contradictory, and that their union is therefore 
forbidden by the laws of formal thinking ? By 
no means. Straight and curve, viewed merely as 
objects of sense, are opposed only as black and 
white, or as biped and quadruped; they cannot, 
that is, be thought as existing at the same time in 
the same subject : but that property which expe- 
rience testifies to have universally accompanied 
curved lines is not, merely by virtue of that expe- 
rience, more incompatible with straight ones, than 
the head which has uniformly accompanied a 
biped body is incompatible with a quadruped one ; 
or than the form which experience has uniformly 
connected with a white surface is incompatible 
with a black one. Nor does the impossibility 
arise from any defect in the simple ideas, such as 



PROLEGOMENA LOGICA. 101 

exists in the case of a man who can form no idea 
of a colour which he has never seen. We have 
all the simple ideas,, or combinations of simple 
ideas, which experience can give : man's head and 
horse's body, in the one case; straight lines and 
space inclosed, in the other. Why is not the 
latter conjunction as easy to the imagination as 
the former ? 

That it is not so, is a matter, not of this or 
that theory, but of psychological fact ; and, as 
such, requires explanation, under any theory what- 
ever. In fact, we may demand, as a sine qua non, 
of every hypothesis concerning the character of 
human knowledge, that it shall accept and account 
for this fact, instead of neglecting or denying it. 
Only two theories can be mentioned as having 
fairly attempted to fulfil this condition. The one 
is that of Leibnitz, who treats mathematical prin- 
ciples as mere analytical judgments, dependent 
on the laws of formal thought. On this sup- 
position, the distinction between Logical and 
Mathematical necessity vanishes altogether °. But 
the solution, though applicable to the general 
axioms which Geometry, in common with all other 
Sciences, tacitly or openly presupposes in so far 
as it contains reasoning at all, fails, when applied 
to those on which all that is especially Geometrical 
depends. By no mere analytical process, as Kant 

Opera, ed. Erclmann, p. 81. 



102 PROLEGOMENA LOGICA. 

has shewn p , can the conception of not enclosing 
a space be elicited from that of two straight lines. 
In this,, and all similar principles, the predicate of 
the proposition is not developed out of, but added 
to the subject. 

The other, and far more satisfactory solution, is 
that of Kant himself. Whatever we are compelled 
to regard as necessary, must be so in consequence 
of laws, not of the object, but of the subject. But 
there are subjective laws of the presentations of 
sense, as well as of the representations of thought. 
We can perceive only as permitted by the laws of 
our perceptive faculties, as we can think only in 
accordance with the laws of the understanding. 
If, then, by a law of my sensibility, I am compelled 
to regard all external objects as existing in space, 
any attributes which are once presented to me, 
as properties of a given portion of space, the 
same must necessarily be thought as existing 
in all space, and at all times. For to imagine a 
space in which such properties are not found, 
would not be to imagine merely a different com- 
bination of sensible phenomena, such as continually 
takes place without any change in the laws of 
sensibility : it would be to imagine myself as per- 
ceiving under conditions other than those to which, 
by a law of my being, I am subjected. The attempt 
to realize such imagination is not a new train of 

p Prolegomena, §.2. 



PROLEGOMENA LOGICA. 103 

thinking ; it is the refusal to think at all. It does 
not inquire what new objects may possibly be 
presented to my present faculties : it requires me 
to determine how objects may appear to a being 
whose faculties are differently constituted from 
mine. Thought, as has already been observed, is 
representative, and can only be exercised on objects 
presented to it. It is therefore restricted by the 
conditions under which alone such presentation 
is possible. If I am to exercise my thought on 
sensible objects at all, I must think of such objects 
under such determinations as the conditions of my 
sensibility require. 

Geometrical principles cannot, therefore, pro- 
perly be called laws of thought ; inasmuch as 
they do not govern every operation of the think- 
ing faculty, but only regulate the application of 
thought to a special class of objects. But they 
are laws relating to the subjective condition of one 
portion of our intuitions, those, namely, which are 
presented to the senses, the condition of their 
presentation being Space. But a condition is 
discernible only in conjunction with that of which 
it is the condition. Space, therefore, and its laws, 
can be made known to consciousness only on the 
occasion of an actual experience of sense. Hence 
the twofold character of Geometrical principles : 
empirical, as suggested in and through an act of 
experience ; necessary, as relating to the conditions 



104 PROLEGOMENA LOGICA. 

under which alone such experience is possible to 
human faculties q . 

The same considerations will explain another 
important feature of Geometrical judgments, in 
which they present a striking contrast to truths 
properly called empirical. Imagination plays its 
part in both ; but in the former case it determines, 
in the latter it is determined by the phenomena 
given in experience. The mental image, which 
I can form of this or that individual, possesses 
more or less of truth and reality, as it represents 
with more or less accuracy the features of the 
sensible object ; just as the value of a portrait 
depends on the accuracy with w T hich it represents 
the features of the original. The imagination, 
again, may of itself form new combinations of 
attributes ; but these also are hypothetically re- 
garded as real or fictitious, according as we may 
or may not hereafter discover such combinations 
to exist in sensible objects. But in Geometry 

q This character of the special axioms of Geometry is 
remarkably expressed in the language of Aristotle. For 
example, aio~6r)o-is, oi>x V t&v ISlcov, aXX ola alcrOavo/jLeBa ort 
to iv rols [xad^fxaTLKols ecrxarov rpiyavov. Eth. Nic. vi. 9. And 
again, Tavra §' io-Tiv olov opav rjj vorjo-ei. Anal. Post. i. 12. 
With which may be compared the language of Kant, Logik, 
§.85. " Die ersten konnen in der Anschauung dargestellt 
werden." Had Aristotle been aware of the distinction between 
the analytical and the synthetical axioms, he might almost 
have anticipated Kant's view of the whole question. 



PROLEGOMENA LOGICA. 105 

the case is reversed. Its propositions are primarily 
and necessarily true of objects existing in the imagin- 
ation ; they are only secondarily and hypothetically 
true of sensible objects, in so far as they conform 
to the imaginary model. If there is such a thing 
in the visible world as a perfect triangle, its angles 
are equal to two right angles. But if there is not, 
the proposition is still true of the triangle as it 
exists in my imagination. And the whole of Geo- 
metry, as a speculative science, would be unaffected 
by the annihilation of every material square or 
triangle in existence ; whatever might become of 
its merely approximate applications to purposes of 
practical utility. Whereas the truths of Zoology, or 
Botany, or Mineralogy, are dependent entirely on 
the existence of animals, or plants, or minerals, not 
as images within the mind, but as entities without. 
The cause of this distinction is manifest from what 
has been said above. The truths of Geometry, 
though subsequent to, are not consequent on, ex- 
perience : they relate, not to the empirical figures 
of body, but to the figures of that space upon 
which sensible experience is dependent. They 
are therefore unaffected by the destruction of the 
visible bodies, and could only become fictitious by 
the annihilation of space itself. But the truths of 
Physical Science depend upon experience alone : 
they are true of the objects only as actually pre- 
sented to the senses ; and their reality depends 
entirely on the real existence of the objective type. 



106 PROLEGOMENA LOGICA. 

As Geometry is a science of necessary truths 
relating to continuous quantities or magnitudes,, so 
Arithmetic is a science of necessary truths relating 
to discrete quantities or numbers. The two sciences, 
however, present some important features of 
distinction. Almost all the truths of Geometry 
are deductive. It contains very few axioms, pro- 
perly so called, i. e. synthetical judgments, derived 
immediately from the intuition of space ; and its 
processes consist in the demonstration of a multi- 
tude of dependent propositions, from the combin- 
ation of these axioms with analytical principles. 
On the other hand, the fundamental operations of 
Arithmetic, Addition, and Subtraction r , present to 
us a vast number of synthetical judgments ; each 
of which, however, is derived immediately from 
intuition, and cannot, by any reasoning process, be 
deduced from any of the preceding ones s . Pure 
Geometry cannot advance a step without demon- 
stration ; and its processes are therefore all reducible 

r " Though in some things, as in numbers, besides adding 
and subtracting, men name other operations, as multiplying 
and dividing, yet are they the same ; for multiplication is but 
adding together of things equal; and division, but subtracting 
of one thing, as often as we can." Hobbes, Leviathan, part i. 
ch. 5. 

s Subtraction may be demonstrated from Addition, if all the 
truths of the latter be supposed given, or vice versa; though 
it is simpler to regard Subtraction as an independent process 
of denumeration, as is done by Condillac, Langue des Calcids, 
ch. 1 . But no result of either can be derived from a preceding 
result of the same operation. 



PROLEGOMENA LOGICA. 107 

to the syllogistic form. Pure Arithmetic contains 
no demonstration ; and it is only when its calculus 
is applied to the solution of particular problems, 
that reasoning takes place, and the laws of syllo- 
gism become applicable. It is not reasoning which 
tells us that two and two make four * ; nor, when 
we have gained this proposition, can we in any 
way deduce from it that two and four make six. 
We must have recourse in each separate case to 
the senses or the imagination, and, by presenting 
to the one or the other a number of individual 
objects corresponding to each factor separately, 
envisage the resulting sum u . The intuition thus 

* Nothing at first sight can appear more satisfactory than 
Leibnitz's proof of this proposition. Nouv. Essais, 1. iv. ch. 7. 
But that demonstration assumes the definitions of the higher 
numbers, (2 is ] -f- 1 ; 3 is 1 -|- 1 -f- 1, &c.) and this, as will 
hereafter appear, is in fact begging the whole question. The 
real point at issue is not whether 4 and 2 + 2 are at bottom 
identical; so that, both being given, an analysis of each will 
ultimately shew their correspondence ; but whether the former, 
notion, definition and all, is contained in the latter. In other 
words, whether a man who has never learned to count beyond 
two, could obtain three, four, five, and all higher numbers, by 
mere dissection of the notions which he possesses already. 
This remark applies also to Stewart, Elements, vol. ii. ch. 1. 
and to Hegel's attempted critique of Kant, Werke, vol. v. 
p. 275. 

u See Kant, Kritik der r. V. p. 70.3. I have availed myself 
of the term envisage, as the best English equivalent that has 
yet been proposed to the German anschauen, a word which is 
applied generally to any presentation of individual objects, in 
sense or imagination. Etymologically, both the German and 
the English word are drawn from the sense of sight only. 



108 PROLEGOMENA LOGICA. 

serves nearly the same purpose as the figure in a 
geometrical demonstration ; with the exception, 
that in the latter case the construction is adopted 
to furnish premises to a proposed conclusion ; while 
in the former, it gives us a judgment which we 
have no immediate purpose of applying to any 
further use. 

An apparent objection, which meets us at the 
outset, must not be left unnoticed. If the results 
of Arithmetic are altogether intuitive, how is it 
that they extend to cases of which sense has never 
furnished us with the occasion of judging ? I may 
have never seen a thousand objects of any kind 
together, yet I am as fully convinced that 976 + 
24 = 1000, as I am that 2 + 2 = 4, of which 
I see instances every day of my life. And, even if 
I have seen examples of the former as well as of 
the latter, how far does the observed fact help in 
the formation of the judgment ? Is my sight so 
acute, that I can distinguish at a glance a group of 
1000 objects from one of 999? Can I then in any 
case be said to have seen the fact verified ? And if 
not, how is it that I do not merely know that what 
I have seen in a single case must be true univer- 
sally, but even can be assured of the necessity of 
truths which I have never accurately observed in 
any actual instance ? 

If uniformity alone were to be consulted, the substantive 
Anschauung, usually translated intuition, should be rendered 
by envisaging. 



PROLEGOMENA LOGICA . 109 

This objection is based on a confusion of intui- 
tion in general with the special presentations of 
sight x . When the propositions of Arithmetic are 
said to be intuitive, it does not follow that their 
truth must have been observed in visible instances; 
that we must have seen, for example, that two and 
three make five, in lines, or pebbles, or the fingers 
of the hand. It implies only that we must have 
perceived the truth of the proposition in some 
individual series, it may be of visible objects, it may 
be of audible sounds, it may be of states of our own 
minds present to internal observation. In none 
of these cases do we deal with representative con- 
cepts, but with individual objects presented to the 
external or internal sense. 

Now how, as a matter of fact, are arithmetical 
judgments usually formed ? We see inexperienced 
calculators arrive at their results by running 
through, orally or mentally, the several units of 
the numbers to be added together. If we do not 
remember that 18 and 7 make 25, as readily as that 
2 and 2 make 4, we supply the defect by summing 
up severally, 19, 20, 21, &c. The artificial aids to 
which we have recourse in larger sums, by adding 
up, for instance, the corresponding digits in separate 
columns, are but abbreviated steps of the same 
process. 

x A confusion to which Kant himself has perhaps in some 
degree contributed, by representing (Proleg. §. 2.) five visible 
points as the intuition of the number; thus by implication 
connecting Arithmetic with space rather than with time. 



110 PROLEGOMENA LOGICA. 

Setting aside, as belonging to art rather than 
science, all those methods whose aim is merely to 
extend or facilitate already existing processes, the 
psychological foundation of Arithmetic is to be 
found in the consciousness of successive mental 
states ; and its earliest actual process consists 
in giving names to the several members of the 
series. Such a process, which may be denomi- 
nated natural, as distinguished from artificial 
numeration, would proceed steadily forward, from 
one member arbitrarily selected as the starting 
point, acknowledging no relation between the 
several steps, beyond that of succession to its 
predecessor, until the computation ceased from 
the inability of the memory to carry on the series. 
Such a system, however limited in its practical 
results, would rest on precisely the same found- 
ation as the more perfect methods which art has 
supplied us, and will consequently contain all the 
data required for determining the nature of the 
necessary truths of Arithmetical Science. 

As Arithmetic, as well as Geometry, contains 
such truths, it must equally be regarded as founded 
on an internal law or condition of our mental 
constitution. This condition is that of Time, a 
condition which governs .not merely our external 
perceptions, but our universal consciousness of all 
that takes place within or without ourselves. 
Every successive modification of the conscious 
mind can be made known to us only as a change 



PROLEGOMENA LOGICA. Ill 

of state ; a change which is only possible under 
the condition of succession in time, — a transition 
from an earlier to a later phase of consciousness. 
Of Time, as an absolute existence, we cannot 
form any idea whatever : it is made known to us 
only as the condition or form of successive states 
of consciousness. To ask, therefore, whether 
Time has any existence out of our own minds, 
is, in the only intelligible mode of putting the 
question, to ask whether other orders of intelligent 
beings are subject to the same conditions of intel- 
ligence as ourselves ; whether they, like us, are 
conscious of various mental states, one succeeding 
another. Put in this form, the question is suf- 
ficiently intelligible, but obviously one which we 
have no data for determining : put in any other 
form, it is absolutely void of meaning, it contains 
not the material for thought, but only a negation 
of all thinking whatever. 

It might indeed be argued, with some show of 
probability, that the condition of successive con- 
sciousness is essentially the condition of a finite 
and imperfect intelligence, consequent only upon 
its very limited power of simultaneous conscious- 
ness 57 . The scholastic doctrine of an eternal Now, 
or nunc stans, so contemptuously treated by Hobbes, 
in this respect contains assuredly no prima facie 
absurdity 2 . The error of such speculations is of 

y Vide Boeth. De Consol. Phil. lib. v. pros. vi. 

z It is surprising to see how near some of the earlier views 



112 PROLEGOMENA LOGICA. 

another kind. It consists in mistaking the negation 
of all thought for an act of positive thinking. As 
our whole personal consciousness is subject to the 
condition of successiveness, we can form no positive 
notion of a different state : we only know that it 
is something which we have never experienced. 
The nature and attributes of an Infinite Intel- 
ligence must be revealed to us in a manner accom- 
modated to finite capacities : how far the accom- 
modation extends, we have no means of deter- 
mining ; as we cannot examine the same data with 
a different set of faculties. The importance of this 
distinction between positive and negative thinking 
will be more closely examined hereafter. 

on this point approached to, without actually arriving at, the 
doctrine of Kant. Had the question been considered sub- 
jectively as well as objectively, on the psychological as well as 
on the metaphysical side, the most important conclusion of 
the critical philosophy would have been anticipated. When 
Hobbes, in his controversy with Bramhall, said, " I never 
could conceive an ever-abiding now" he was right; but he 
was wrong in supposing that this was decisive of the point at 
issue. We can only conceive in thought what we have expe- 
rienced in presentation ; and all our past presentations have 
been given under the law of succession. But this does not 
enable us to decide what may be the condition of other than 
human intelligences. In this respect, the remark of Bramhall 
is exactly to the purpose. " Though we are not able to com- 
prehend perfectly what God is, yet we are able to comprehend 
perfectly what God is not; that is, He is not imperfect, and 
therefore He is not finite." Beid (Intell. Powers, Essay iii. 
ch. 3.) treats the nunc stems as a contradiction, which it is 
not. 



PROLEGOMENA LOGICA. 113 

But to return to the question of mathematical 
necessity. To construct the whole science of 
Arithmetic, it is only requisite that we should be 
conscious of a succession in time, and should be 
able to give names to the several members of the 
series. And since in every act of consciousness 
we are subject to the law of succession, it is im- 
possible in any form of consciousness to represent 
to ourselves the facts of Arithmetic as other than 
they are. To the art, not to the science, of 
Arithmetic belong all the methods for facilitating 
calculation which imply any thing more than the 
mere idea of succession. Such a method, and a 
powerful one, is afforded by the invention of Scales 
of Notation, in which, to the idea of succession is 
added that of recurrence ; the series being regarded 
as commencing again from a second unit, after 
proceeding continuously through a certain number 
of members, ten, for example, as in the common 
system. Hence we are enabled to repeat over 
again, in the second and subsequent decades, the 
operations originally performed in the first, and 
thus indefinitely to extend our calculus in the 
form of a continually recurring series ; but the 
calculus, though thus rendered infinitely more 
efficacious as an instrument, remains in its psy- 
chological basis unaltered. 

From these considerations it follows, that the 
several members of an arithmetical series are 

i 



114 PROLEGOMENA LOGICA. 

incapable of definition. Succession in time, and 
the consciousness of one, two, three, &c. are not 
complex notions abstracted from and after a multi- 
tude of intuitions, but simple immediate intuitions, 
differing, as far as numeration is concerned, only in 
the order of their presentation. They are not by 
any act of thought compounded, the later from 
the earlier : they cannot be resolved into any 
simpler elements of consciousness, presentative or 
representative, being themselves the a 'priori con- 
ditions of consciousness in general. Hence the 
failure of all attempts to analyse numerical calcu- 
lation as a deductive process. Leibnitz, and sub- 
sequently Hegel, have endeavoured to represent 
the arithmetical processes as operations of pure 
analysis. Assuming, for example, 12 and 7 and 5, 
as given concepts, they shew that the first may be 
ultimately analysed into the same constituent units 
as the two last ; and this is regarded as an expla- 
nation of the whole process of Addition. They 
overlook the fact that, in that process, 12 is not 
given, but has to be determined by the addition of 
the other two numbers. Arithmetic is not, like 
Geometry, a science whose definitions are genetic 
and preliminary to its processes. The analysis of 
any number into its constituent units presupposes 
the whole operation which it professes to give rise 
to. We may call, if we please, such an analysis 
definition; but we must not suppose that it in any 



PROLEGOMENA LOGICA. 115 

degree corresponds to the definitions of Geometry, 
or answers the same purpose in the operations of 
the science 1 . 

The above considerations are sufficient for our 
present purpose, which is to determine the psycho- 
logical basis of mathematical judgments, and their 
consequent special character as necessary truths, 
in a distinct sense from that in which the term is 
applied to logical or physical principles. Mathe- 
matical judgments are synthetical, based on the 
universal conditions of our intuitive faculties, and 
are necessary, not, properly speaking, as laws of 
thought, but because thought can only operate in 
conjunction with matter given by intuition, and 
intuition cannot be emancipated from its own sub- 
jective conditions. Hence we are compelled to 
think of our intuitions under the same laws accord- 
ing to which they are invariably realized in con- 
sciousness. Judgments of logical necessity, on the 
other hand, are analytical, and rest on the laws of 

a Writers of a very different school from that of Leibnitz 
or Hegel have fallen into a similar error with regard to the 
nature of arithmetical processes. Mr. Mill, for example, 
regards the whole science of numbers as derived from the 
common axioms concerning equality, and the definitions of 
the several numbers. Stewart appears to have been of the 
same opinion. On the contrary, the whole essentials of the 
science must be in existence before the so-called definitions 
can be formed. The applications of the calculus as an instru- 
ment must not be confounded with its essential constituents 
as a science. 

i2 



116 PROLEGOMENA LOG1CA. 

thought properly so called. Their analytical cha- 
racter is a necessary consequence of the constitu- 
tion of the thinking faculty, and is so far from being 
a proof of the unsoundness or frivolity of logical 
speculations, that it is the strongest evidence of 
their truth and scientific value, and leads to most 
important consequences, both in Logic and in 
Psychology. 

The nature of these judgments, as well as of 
those distinguished as metaphysically necessary, 
will be examined in the following chapters. 



CHAP. V. 

ON THE PSYCHOLOGICAL CHARACTER, OF METAPHYSICAL NECESSITY. 

A distinction between necessary and contingent 
matter is found, somewhat out of place it is true, 
but still it is found, in most of the older, and, 
among English writers, in most also of the recent 
treatises on Logic a . The boundaries of each, 
however, are not in the majority of instances de- 
termined with any approach to accuracy. Among 
the schoolmen, the favourite example of a pro- 
position of the highest degree of necessity was 
omne animal rationale est risibile, an example con- 
sistent enough with the mediaeval state of physical 
science, but which in the present day will scarcely 
be allowed a higher degree of certainty than be- 

a Matter in this sense must not be confounded with the 
modality recognised by Aristotle and by most of the modem 
German Logicians. The former is an understood relation 
between the terms of a proposition; the form of the pro- 
position being in all cases "A is B;" and is supposed to be 
of use in determining the quantity of indefinites. The latter 
is an expressed relation ; the form of the necessary proposition 
being "A must be B;" and this is applicable to universal and 
particular propositions indifferently. The admission of the 
latter is still a point of dispute among eminent authorities : 
the admission of the former will be tolerated by no Logician 
who understands the nature of his own science. 



118 PROLEGOMENA LOGIC A. 

longs to any other observed fact in the constitution 
of things. An eminent modern Logician gives as 
an example of a proposition in necessary matter, 
" all islands are surrounded by water/' an example 
which is only valid in so far as the predicate forms 
part of the notion of the subject, and which, 
therefore, has no other necessity than belongs to 
all analytical judgments, a necessity derived from 
the form, not from the matter \ The distinction 
itself, though altogether out of place when Thought 
is considered merely in its relation to Logic, is, in 
a psychological point of view, of considerable im- 
portance. The following remarks will, it is hoped, 
throw some light on its true character. 

All analytical judgments are necessary; but they 
cannot properly be said to be in necessary matter. 
They are all ultimately dependent on the Prin- 
ciples of Identity and Contradiction, " Every A is 
A," and " No A is not A:" c principles, the neces- 

b Examples of this kind were indeed indiscriminately ad- 
mitted by the scholastic Logicians, who held any proposition 
to be in necessary matter, in which the predicate was part 
of the essence, or necessarily joined to the essence, of the 
subject. But this classification, though tenable perhaps in 
connection with realist metaphysics, is inconsistent with an 
accurate discrimination between the matter and the form of 
thought. 

c Kant, Kritik der r. V. p. 133. Proleg. §. 2. He derives all 
analytical judgments from the Principle of Contradiction. 
It would be more accurate to distinguish this principle from 
that of Identity, and to derive the negative judgments from 
the former, the affirmative from the latter. 



PROLEGOMENA LOGICA. 119 

sity of which arises solely from their form, without 
any relation to this or that matter. That every 
triangle has three sides, arises from a mere analysis 
of the notion of a triangle ; as that every island is 
surrounded by water, arises from a mere analysis of 
the notion of an island. This necessity is derived 
solely from the laws of formal thinking. 

Of synthetical judgments, every statement of a 
physical fact is in contingent matter ; at least if 
the opposite term be used in its highest sense. 
However rigidly certain phenomena may be 
deduced from the assumption of a general law of 
nature, the law itself remains nothing more than 
an observed fact, of which we can give no other 
explanation, than that it was the will of the 
Creator to constitute things in a certain manner. 
For example : that a body in motion, attracted by 
a force varying inversely as the square of the 
distance, will describe an ellipse having the centre 
of attraction in one of the foci, — this is matter of 
demonstration : but that the earth is such a body, 
acted upon by forces of this description, is matter 
of fact, of which we can only say that it is so, and 
that it might have been otherwise. The original 
premise being thus contingent, all deductions from 
it are materially contingent likewise. 

The same is the case with all psychological 
judgments, so far as they merely state the fact 
that our minds are constituted in this or that 
manner. But there is one remarkable difference 



120 PROLEGOMENA LOGICA. 

between this contingency, and that which is pre- 
sented by physical phenomena. The laws of the 
latter impose no restraint on my powers of thought: 
relatively to me, they are simply universally ob- 
served facts. There is therefore no impediment 
to my uniting in a judgment any two notions once 
formed; though the corresponding objects cannot, 
consistently with existing laws of nature, be united 
in fact. I may thus conceive a mountain moving, 
or a stone floating on the water; though my expe- 
rience has always presented to me the mountain as 
standing, and the stone as sinking. But as regards 
Psychology: the powers of my mind cannot be 
presented to consciousness, but under one deter- 
minate manifestation. The only variety is found 
in the objects on which they operate. I am thus 
limited in my power of forming notions at all, in 
all cases where I am, by mental restrictions, pre- 
vented from experiencing the corresponding in- 
tuition. I have thus a negative idea only of the 
nature of an intelligent being constituted in a 
different manner from myself; though I have no 
difficulty in supposing that many such exist. I 
can suppose, for instance, that there may exist 
beings whose knowledge of material objects is not 
gained through the medium of bodily senses, or 
whose understanding has a direct power of in- 
tuition ; but to conceive such a being is beyond 
my power; conception being limited to the field 
of positive intuitions. In another point of view, 






PROLEGOMENA LOG1CA. 121 

both physical and psychological judgments may 
be called necessary; as the consequence of certain 
established laws, which laws, however, might have 
been otherwise. In this sense, both might be 
classified as hypothetically necessary ,d ; in opposition 
to another class of judgments, those relating to 
human actions, which, as will hereafter appear, 
are, in the fullest sense of the term, contingent. 
For logical purposes, however, the former clas- 
sification is preferable. 

On the other hand, mathematical judgments 
have been almost universally regarded as belong- 
ing to the province of necessary matter 6 . We 
can suppose the possibility of beings existing, 
whose consciousness has no relation to space or 
time at all. We can suppose it possible, that some 
change in our mental constitution might present 
us with the intuition of space in more than three 
dimensions. This is no more than to admit the 
possible existence of intelligent creatures other- 
wise constituted than ourselves, and consequently 
incomprehensible by us. But to suppose the 
existence of geometrical figures, or arithmetical 

d An expression adopted by M. Duval-Jouve, Logique, 
p. 78. 

e Universally among those who have accurately distinguished 
intelligible from sensible magnitude. The objections of Sextus 
Empiricus in ancient, and of Hume in modern times, among 
sceptics, so far as they have any special relation to Geometry, 
as well as those of M. Comte and Mr. Mill, among sensational- 
ists, are mainly based on a confusion of these two. 



122 PROLEGOMENA LOGICA. 

numbers, such as those with which we are now 
acquainted, is to suppose the existence of space 
and time as we are now conscious of them ; and 
therefore, relatively to beings, whose mental con- 
stitution is so far similar to our own. Such a 
supposition, therefore, necessarily carries with it 
all the mathematical relations in which time and 
space, as given to us, are necessarily thought. 
For mathematical judgments strictly relate only 
to objects of thought, as existing in my mind ; 
not to distinct entities, as existing in a certain 
relation to my mind. They therefore imply no 
other existence but that of a thinking subject, 
modified in a certain manner. Destroy this sub- 
ject, or change its modification, and we cannot 
say, as in other cases, that the object may possibly 
exist still without the subject, or may exist in a 
new relation to a new subject ; for the object 
exists only in and through that particular modi- 
fication of the subject, and, on any other sup- 
position, is annihilated altogether. It is thus 
impossible to suppose, that a triangle can, in 
relation to any intelligence whatever, have more 
or less than two right angles, or that two and two 
should not be equal to four ; though it is possible 
to suppose the existence of beings destitute of the 
idea of a triangle or of the number two. This is 
necessary matter, in the strict sense of the term ; a 
relation which our minds are incapable of reversing, 
not merely positively, in our own acts of thought, 



PROLEGOMENA LOGICA. 123 

but also negatively, by supposing others who can 
do so. 

There is one other science which has frequently 
been supposed to share this necessity with Mathe- 
matics. Metaphysics, though, so far as it deals 
in merely analytical judgments, it has been suf- 
ficiently shewn by Kant to be incapable of leading 
to any scientific results, is frequently regarded as 
possessing a certain number of synthetical axioms, 
which, under the various names of Principles of 
Necessary Truth, Fundamental Laws of Human 
Belief, and sometimes even (however incorrectly) 
of Laws of Thought f , have held a prominent 
place in various systems of philosophy down to 
the present time. Two of these principles may 
be especially selected for examination, partly on 
account of the importance attached to them by 
eminent writers, and partly on account of their 
relation to the Forms of Thought recognised by 
Logic. 

1. The Principle of Substance. All objects of 



f This nomenclature is sanctioned by the authority of 
M. Koyer-Collard. " Trois lois de la pensee concourent 
dans la perception. 

1°. L etendue et l'impenetrabilite ont un sujet auquel elles 
sont inherentes, et dans lequel elles coexistent. 

2°. Toutes les choses sont placees dans une duree absolue, 
a laquelle elles participent comme si elles etaient une seule 
et meme clrose. 

8°. Tout ce qui commence a exister a ete produit par une 
cause." Jouffroy's Reid, vol. iv. p. 447. 



124 PROLEGOMENA LOGICA. 

perception are Qualities which exist in some Subject 
to which they belong. 

2. The Principle of Causality g . Whatever be- 
gins to exist must take place in consequence of 
some Cause. 

" I perceive/' says Reid, " in a billiard ball, figure, 
colour, and motion ; but the ball is not figure, nor 
is it colour, nor motion, nor all these taken toge- 
ther ; it is something that has figure, and colour, 
and motion. This is a dictate of nature, and the 
belief of all mankind V 

On the other hand, Bishop Berkeley had laboured 
hard to prove that it was much more consonant to 
nature, and to the common sense of mankind, to 
deny altogether the existence of this imperceptible 
substance, the supposed support of perceptible 
attributes. " I do not argue," he says, " against 
the existence of any one thing that we can appre- 
hend, either by sense or reflection. That the things 

§ Called also the Principle of Sufficient Reason, or of Deter- 
mining Reason ; though these expressions, as Sir W. Hamilton 
has observed, are used ambiguously to denote, conjunctly and 
severally, the two metaphysical or real principles ; 1°. Why a 
thing is; 2°. Why a thing becomes or is produced; and, 3°. The 
logical or ideal principle, Why a thing is known or conceived. 
(Hamilton on Keid, p. 624.) Cf. Leibnitz's fifth Letter to 
Clarke, §. 125. where he states the principle in three forms. 
" Ce principe est celui du besoin d'une raison sumsante, pour 
qu'une chose existe, qu'un evenement arrive, qu'une verite ait 
lieu." For a criticism on the principle as thus given, see 
Herbart, Lehrbuch zur Einleitung in die Philosophic, §.39. 

h Intellectual Powers, Essay ii. ch. 1 9. 



PROLEGOMENA LOGICA. 125 

I see with mine eyes and touch with my hands do 
exist, really exist, I make not the least question. 
The only thing whose existence we deny, is that 
which philosophers call matter, or corporeal sub- 
stance. And in doing of this, there is no damage 
done to the rest of mankind, who, I dare say, will 
never miss it. The atheist indeed will want the 
colour of an empty name to support his impiety ; 
and the philosophers may possibly find, they have 
lost a great handle for trifling and disputation." 

" It will be urged," he continues, " that thus 
much at least is true, to wit, that we take away all 
corporeal substances. To this my answer is, that 
if the word substance be taken in the vulgar sense, 
for a combination of sensible qualities, such as 
extension, solidity, weight, and the like : this we 
cannot be accused of taking away. But if it be 
taken in a philosophic sense, for the support of 
accidents or qualities without the mind ; then indeed 
I acknowledge that we take it away, if one may be 
said to take away that which never had any exist- 
ence, not even in the imagination \" 

But after Berkeley came Hume, who applied to 
the phenomena of internal perception the same 
process of reasoning which Berkeley had applied 
to the external. Within myself, he argued, I am 
conscious only of impressions and ideas. The 
substance called Mind is a mere fiction, imagined 
for the support of these, as the substance called 

' Principles of Human Knowledge, xxxv. xxxvii. 



126 PROLEGOMENA LOGICA. 

Matter is imagined for the support of sensible 
qualities 1 ". In opposition to these sceptical con- 
clusions, Reid and his disciples appealed to the 
authority of certain "universally acknowledged 
axioms, distinguished as Principles of Common 
Sense, or Fundamental Laws of Human Belief, of 
which we can give no other account than that 
such is our constitution, and we must think accord- 
ingly. One of these is the Principle of Substance, 
mentioned above. 

It is necessary to speak with diffidence on a 
point disputed by philosophers of such eminence ; 
but if there be any truth in the psychological dis- 
tinction between Thought and Intuition, noticed 
in my first chapter, it will appear that the Scottish 
philosophers, in endeavouring to overthrow Hume 
and Berkeley at once, abandoned the only position 
from which an attack might have been successfully 
made on either of them separately. Hume's phi- 
losophy is not a legitimate development of Berkeley's, 
unless we allow that our consciousness of mind, as 
well as of matter, is representative only. If it be true 
that neither mental nor material substance, as distin- 
guished from the various states and attributes of 
either, is in any manner presented intuitively, the 
two theories must stand or fall together. And this 
point is over and over again conceded by Reid and 
Stewart '. 

k Treatise of Human Nature, part iv. sect. 5, 6. 

1 For example, " The attributes of individuals is all that we 



PROLEGOMENA LOGICA. 127 

Under this concession, the appeal to a funda- 
mental law of belief is insufficient. Such a law 
can only state the fact, that we are by our consti- 
tution compelled to believe in a certain relation 
between two given notions : it does not explain how 
either of such notions could have entered into the 
mind in the first instance. But the appeal becomes 
self-contradictory, in the hands of any one who 
admits the views of Locke, or of Kant, concerning 
the limits of the understanding m . Either a pre- 
sentative origin must be found for the notions of 
substance and cause, or we must admit that, in 

distinctly conceive about them. It is true, we conceive a 
subject to which the attributes belong; but of this subject, 
when its attributes are set aside, we have but an obscure and 
relative conceptions whether it be body or mind." Eeid, Int. 
Powers, Essay v. ch. 2. " It is not matter, or body, which I 
perceive by my senses ; but only extension, figure, colour, and 
certain other qualities, which the constitution of my nature 
leads me to refer to something which is extended, figured, 
and coloured. The case is precisely similar with respect to 
mind. We are not immediately conscious of its existence, 
but we are conscious of sensation, thought, and volition ; 
operations which imply the existence of something which 
feels, thinks, and wills." Stewart, Elements, Introd. part i. 

m Yet Kant, no less than Eeid, allows that we are not 
immediately conscious of mind, but only of its phenomena. 
In his hands, however, the concession is perfectly suicidal, 
and forms the weak part of the Critical Philosophy. The 
reader who bears this inconsistency in mind, may perhaps 
find an easier solution to some of Kant's Paralogisms and 
Antinomies of Pure Eeason than could have been given by the 
author himself. On this subject, the admirable remarks of 
M. Cousin, in his Sixth Lecture on Kant, should be consulted. 



] 28 PROLEGOMENA LOGICA. 

these instances, the act of thought has created its 
own objects. 

We are therefore compelled to ask, Is this 
asserted analogy between our modes of conscious- 
ness in relation to matter and mind really tenable ? 
Does it not rather appear a flat self-contradiction 
to maintain, that I am not immediately conscious 
of myself, but only of my sensations or volitions ? 
Who then is this / that is conscious, and how can 
I be conscious of such states as mine ? In this 
case, it would surely be far more accurate to say, 
not that I am conscious of my sensations, but that 
the sensation is conscious of itself : but, thus worded, 
the glaring absurdity of the theory would carry 
with it its own refutation. 

The one presented substance, the source from 
which our data for thinking on the subject are 
originally drawn, is myself*. Whatever may be 
the variety of the phenomena of consciousness, 
sensations by this or that organ, volitions, thoughts, 



n This has been clearly seen by an illustrious French 
disciple of the Scottish philosophy, who has thus supplied 
a marked deficiency in the system of his masters. " Le moi," 
says M. Royer-Collard, " est la seule unite qui nous soit 
donnee immediatement par la nature ; nous ne la rencontrons 
dans aucune des choses que nos facultes observent. Mais 
l'entendement qui la trouve en lui, la met hors de lui par 
induction, et d'un certain nombre de choses coexistantes il 
cree des unites artificielles." Jouffroy's Reid, vol. iv. p. 850. 
But the French writer to whom this portion of philosophy is 
most indebted is Maine de Biran. 



PROLEGOMENA LOGICA. 129 

imaginations, of all we are immediately conscious 
as affections of one and the same self. It is not 
by any after effort of reflection that I combine 
together sight and hearing, thought and volition, 
into a factitious unity or compounded whole: in 
each case I am immediately conscious of myself 
seeing and hearing, willing and thinking. This 
self-personality, like all other simple and immediate 
presentations, is indefinable; but it is so, because it 
is superior to definition. It can be analysed into 
no simpler elements, for it is itself the simplest of 
all : it can be made no clearer by description or 
comparison, for it is revealed to us in all the clear- 
ness of an original intuition, of which description 
and comparison can furnish only faint and partial 
resemblances. 

The extravagant speculations in which Metaphy- 
sicians attempted to explain the nature and pro- 
perties of the soul as it is not given in conscious- 
ness, furnish no valid ground for renouncing 
all inquiry into its character as it is given, as a 
power, conscious of itself . That there are many 
metaphysical, or rather psychological difficulties, 
still unsolved, connected with this view of the sub- 
ject, must be allowed p ; but so long as we remain 
within the legitimate field of consciousness, we are 

See Cousin, Legons sur Kant, p. 197. Damiron, Psychologie, 
1. i. ch. iv. 

p See Herbart, Lehrbuch zur Einleitung in die Philosophie, 
§. 124. Hauptpuncte der Metaphysik, §. 11, 12. 

K 



130 PROLEGOMENA LOGICA. 

not justified in abandoning them as insoluble. To 
this class belongs the question of Personal Identity, 
or the reference of earlier and later states of con- 
sciousness to the same subject; an immediate con- 
sciousness being of present objects only. The 
following question may perhaps furnish a hint of 
the data from which the solution of this problem 
may be attempted. Time and Space are given as 
forms or conditions of the several phenomena of 
internal or external consciousness ; but are the 
same conditions strictly applicable to the conscious 
subject itself? I may speak, accurately enough, 
of my earlier or later thoughts or feelings ; but, apart 
from metaphor, can I, with any philosophical accu- 
racy, speak of an earlier or later self, even as a 
mere logical distinction for the purpose of after- 
wards identifying the two ? To identify is to connect 
together in thought objects given under different 
relations of space or time, as when I pronounce 
the sovereign now lying on my table to be nume- 
rically one with that which I received yesterday at 
the Bank. But is the conscious self ever given 
under these different relations at all ? Is it not 
rather that from which our original notion of 
numerical identity was drawn, and which cannot 
be subjected to later and analogical applications of 
the same idea ? 

This one presented substance, myself, is the 
basis of the other notions of substance which are 
thought representatively in relation to other phe- 



PROLEGOMENA LOGICA. 131 

nomena. When I look at another man, I do not 
perceive his consciousness. I see only a com- 
pound body, of a certain form and colour, moving 
in this or that manner. I do not immediately 
know that he perceives, feels, and thinks, as I do 
myself. He may be an exquisitely formed puppet, 
requiring perhaps more mechanical skill in the 
construction than has ever been attained by man, 
but still a mere machine-, a possible piece of clock- 
work. When I attribute to him personality and 
consciousness, I mediately and reflectively transfer 
to another that of which I am directly cognisant 
only in myself. In this case, the phenomena are 
given in a sensible intuition ; the substance is added 
to them by a representative act of thought. 

Beyond the range of conscious beings, we can 
have only a negative idea of substance. The name 
is applied in relation to certain collections of sensible 
phenomena, natural or artificial,, connected with 
each other in various ways; by locomotion, by 
vegetation, by contributing to a common end, by 
certain positions in space. But here we have no 
positive notion of substance distinct from phe- 
nomena. I do not attribute to the billiard ball a 
consciousness of its own figure, colour, and motion; 
but, in denying consciousness, I deny the only form 
in which unity and substance have been presented 
to me. I have therefore no data for thinking one 
way or the other on the question. Some kind of 
unity between the several phenomena may exist, or 

k2 



132 PROLEGOMENA LOGICA. 

it may not ; but if it does exist, it exists in a 
manner of which I can form no conception ; and if 
it does not exist, my faculties do not enable me to 
detect its absence. 

Such an acknowledgment of the negative cha- 
racter of certain supposed thoughts, i. e. of their 
not being really thoughts at all, is very different 
from scepticism. It does not teach a distrust of 
our faculties within their proper limits, but only 
tells us that they have limits, and that they cannot 
transgress them. In this there is no more of 
paradox, than in asserting that we cannot see a 
man or a tower at a thousand miles' distance. 
The fault of Berkeley did not consist in doubting 
the existence of matter, but in asserting its non- 
existence. If I cannot see a spot a thousand 
miles off, I am, as far as sight is concerned, equally 
incompetent to assert that there is or is not a 
tower standing upon it. In like manner, it is 
characteristic of all mere negative notions, that 
we cannot possibly say whether their supposed 
objects exist or not. To maintain that matter is 
a fiction, invented for the support of attributes, is 
to dogmatize in negation, and, after all, to give a 
partial solution only of the question : for fictions 
as well as facts have their psychological conditions, 
under which alone their invention is possible 9 . 

9 " It seems to be a judgment of nature," says Eeid, (J. P. 
ii. 19.) "that the things immediately perceived are qualities, 
which must belong to a subject; and all the information that 



PROLEGOMENA LOGICA. 



133 



Had Berkeley's theory been accompanied by an 
inquiry into the origin of negative notions and 
their influence on thought and language, it could 
scarcely have given rise either to the extreme 
scepticism of his successor, or to the strange mis- 
understandings of some of his adversaries. 

The conclusion to be drawn from the above 
remarks is sufficiently obvious. The general 
assertion, that all sensible qualities belong to a 
subject, cannot with any propriety be called a 
principle of necessary truth ; inasmuch as it is a 
principle which may be either true or false, and 
we have no means of determining which. Nor is 
it correct to call it a fundamental law of human 
belief; if by that expression is meant any thing 
more than an assertion of the universal tendency 
of men to liken other things to themselves, and to 
speak of them under forms of expression adapted 
to such likeness, far beyond the point where the 
parallel fails. In this point of view, the principle 
in question is an interesting object of psychological 
inquiry ; the more so, inasmuch as, true or false, 
it has determined the forms of speech acquiesced 

our senses give us about this subject, is, that it is that to 
which such qualities belong." In point of fact, our senses 
tell us nothing of the kind ; and, were these our only intuitive 
faculties, we should never have supposed such a subject to 
exist. To refer any belief to a principle of our nature, is 
insufficient, unless we can at the same time psychologically 
account for the origin of the notions which that belief 
implies. 



134 



PROLEGOMENA LOGICA. 



in by all mankind, from the most learned to the 
most ignorant. That acquiescence it is not de- 
sirable to attempt to disturb, for two very sufficient 
reasons. Firstly, because the attempt is sure to 
be unsuccessful ; as men will continue to speak as 
men have spoken before them : Secondly, because 
we have nothing better to substitute in its place ; 
as an opposite form of speech, if such could be 
introduced, would imply an opposite belief, and 
that, for aught we can tell^ may be the wrong one. 
Every possible form of assertion must contain 
some one element which is not a representative 
of thought, but of its negation ; but, when the 
candidates are in this respect equal, the pre- 
sumption is in favour of that which men of all 
ages have instinctively adopted. Even a sleeping 
dog may safely be let lie, when there is no more 
watchful guard to take his place. 

But, though there is thus no speculative reason for 
accepting or rejecting Berkeley's theory as true or 
false, or for attempting to adapt to it common forms, 
of speech, there may, in certain philosophical in- 
quiries, be a regulative reason for accepting or re- 
jecting it as convenient or inconvenient If the 
method of metaphysical research can in any degree 
be simplified by divesting it of the hypothesis of 
a substratum of sensible attributes, this will be a 
sufficient reason for accepting the theory as pro 
tanto valid. Such simplification will not, however, 
be effected by taking the Berkleian theory in its 



PROLEGOMENA LOGICA. 135 

whole extent. The admission of ideas as the 
immediate objects of perception, whether in 
Berkeley's form, as entities distinct from the mind, 
or in Fichte's, as modifications of the mind itself, 
and the necessary consequence, that nothing exists 
except when it is perceived, is too repugnant to 
the common sense of mankind to have any ulti- 
mate value in philosophy. There is still room, 
however, for an attempt to construct a similar 
theory, viewed from the objective side, which, 
banishing the hypothesis of a substratum, shall 
regard the sensible attributes as the things them- 
selves. Whether such a theory would offer any 
ground for constructing Metaphysical Science on 
a sure basis, or whether it would share the fate of 
preceding systems, remains to be seen r . 

Much of the above reasoning is applicable to 
the Principle of Causality likewise. I hold a 
piece of wax to the fire, and it begins to melt 3 . 
Here my senses inform me only of two successive 

r Something of this sort may perhaps be attempted in 
connection with Sir William Hamilton's doctrine of Natural 
Kealism. But that doctrine, admirable as it is in the portions 
that have at present been published, is at present hardly 
enough developed as a whole to allow us to judge of its 
metaphysical bearings. On the really weak side of Berkeley's 
Philosophy, see Appendix, note B. 

s See Locke, Essay, b. ii. ch. 26. who erroneously regards 
the production of change as perceptible by the senses. The 
other and very different origin suggested by the same philo- 
sopher, Essay, b. ii. ch. 21. is the germ of the theory of Maine 
de Biran. 



136 PROLEGOMENA LOGICA. 

phenomena; the proximity of the fire, and the 
melting of the wax. That the one is the pro- 
ductive cause of the other, is an addition to the 
sensible data, which, so far as this particular 
instance is concerned, is not given, but inferred. 
Here, again, it becomes necessary to inquire, 
whether we shall abandon the belief in Causes 
altogether; whether we shall concede that Thought 
alone is competent to create the notion ; or 
whether we can discover any intuition in which 
Causality, as distinct from mere Succession, is 
immediately presented. 

Hume, and subsequently Brown, denied alto- 
gether the existence of Cause in this sense of the 
term. With these philosophers, a cause is nothing 
more than something prior to the change, and 
constantly conjoined with it. " We give the name 
of cause" says Brown, "to the object which we 
believe to be the invariable antecedent of a par- 
ticular change ; we give the name of effect reci- 
procally to that invariable consequent; and the 
relation itself, when considered abstractly, we 
denominate power in the object that is the invari- 
able antecedent, — susceptibility in the object that 
exhibits, in its change, the invariable consequent. 
We say of fire, that it has the power of melting 
metals, and of metals, that they are susceptible of 
fusion by fire, — that fire is the cause of the fusion, 
and the fusion the effect of the application of fire ; 
but in all this variety of words, we mean nothing 



PROLEGOMENA LOGICA. 137 

more than our belief, that when a solid metal is 
subjected for a certain time to the application of 
a strong heat, it will begin afterwards to exist in 
that different state which is termed liquidity, — that 
in all past time, in the same circumstances, it would 
have exhibited the same change, — and that it will 
continue to do so in the same circumstances in all 
future time V 

Thus far Hume and Brown are at one. Into 
the subordinate question at issue between them, 
as to the origin of our belief in the uniformity of 
nature, it is foreign to my present purpose to 
enter. I have at present to do only with that 
portion of the theory in which both philosophers 
are agreed, — the resolution of cause into invariable 
antecedent; concerning which Reid remarks, that 
we may learn from it that night is the cause of 
day, and day the cause of night : for no two 
things have more constantly followed each other 
since the beginning of the world. 

The philosophers of the school of Reid could 
not fairly meet Hume's theory of causation, for 
the same reason that they could not fairly meet 
his theory of substance ; because they denied the 
existence of an immediate consciousness of mind, 
as distinguished from its several states. It was 
easy for Hume to shew that volition is but one 
phenomenon, and motion is but another, and that 
the former is so far from being the necessary 

1 Inquiry into the relation of Cause and Effect, p. 12. 



138 PROLEGOMENA LOGIC A. 

cause of the other, that a stroke of paralysis may 
put an end even to the uniformity of the sequence. 
It was also easy for him to shew that, as the 
motion of the arm is not the immediate consequent 
of the volition, but is separated from it by an inter- 
vening nervous and muscular action of which we 
are unconscious, the one cannot be directly given 
as produced by the other. The intuition of Power 
is not immediately given in the action of matter 
upon matter ; nor yet can it be given in the action 
of matter upon mind, nor in that of mind upon 
matter ; for to this day we are utterly ignorant 
how matter and mind operate upon each other. 
We know not how the material refractions of the 
eye are connected with the mental sensation of 
seeing, nor how the determination of the will 
operates in bringing about the motion of the 
muscles. We can investigate severally the phe- 
nomena of matter and of mind, as we can examine 
severally the constitution of the earth, and the 
architecture of the heavens : we seek the boundary 
line of their junction, as the child chases the 
horizon, only to discover that it flies as we pur- 
sue it. 

There is thus no alternative, but either to 
abandon the inquiry after an immediate intuition 
of power, or to seek for it in mind as determining 
its own modifications n ; — a course open to those who 

u This is clearly and accurately stated by M. Cousin. 
" Cherche-t-on la notion de cause dans Faction de la bille 



PROLEGOMENA LOGICA. 139 

admit an immediate consciousness of self, and to 
them only. My first and only presentation of 
power or causality is thus to be found in my 
consciousness of myself as willing. In every act 
of volition, I am fully conscious that it is in my 
power to form the resolution or to abstain ; and 
this constitutes the presentative consciousness of 
free will and of power. Like any other simple 
idea, it cannot be defined ; and hence the dif- 
ficulty of verbally distinguishing causation from 
mere succession. But every man who has been 
conscious of an act of will, has been conscious of 
power therein ; and to one who has not been so 
conscious, no verbal description can supply the 
deficiency. 

Here again, as in the case of substance, as soon 
as we advance beyond the region of consciousness, 

sur la bille, comme on le faisait avant Hume, ou de la main 
sur la bille, et des premiers muscles locomoteurs sur leurs 
extremites, ou meme dans Faction de la volonte sur le muscle, 
comme l'a fait M. de Biran, on ne la trouvera dans aucun de 
ces cas, pas meme dans le dernier, car il est possible qu'il y 
ait une paralysie des muscles qui rende la volonte impuissante 
sur eux, unproductive, incapable d'etre cause et par con- 
sequent d'en suggerer la notion. Mais ce qu'aucune paralysie 
ne peut empecber, c'est Taction de la volonte sur elle-meme, 
la production d'une resolution, c'est-a-dire une causation toute 
spirituelle, type primitif de la causalite, dont toutes les actions 
exterieures, a commencer par l'effort musculaire, et a fmir par 
le mouvement de la bille sur la bille, ne sont que des symboles 
plus ou moms infideles." Fragments Philosophiques, Preface de 
la premiere edition. 



140 PROLEGOMENA LOG1CA. 

we find ourselves in the midst of negative notions, 
which we can neither conceive, nor affirm, nor 
deny. Our clearest notion of efficiency is that of 
a relation between two objects, similar to that 
which exists between ourselves and our volitions x . 
But what relation can exist between the heat of 
fire and the melting of wax, similar to that between 
a conscious mind and its self-determinations ? Or, 
if there is nothing precisely similar, can there be 
any thing in any degree analogous ? We cannot 
say that there is, or, if there is, how far the analogy 
extends, and how and where it fails. We can form 
no positive conception of a power of this kind: 
we can only say, that it is something different 
from the only power of which we are intuitively 
conscious. But, on the other hand, we are not 
warranted in denying the existence of any thing 
of the kind ; for denial is as much an act of 
positive thought as affirmation, and a negative 
idea furnishes no data for one or the other. 

Before we can generally assert, as a principle of 
necessary truth, that whatever begins to exist must 
have a cause, we must, therefore, determine what 
meaning we are to attach to the term cause. As 
given in consciousness, it means the power of a 
voluntary agent : as interpreted by Hume and his 
followers, it means some one invariable antecedent 
phenomenon or aggregate of phenomena 7 . These 

x See Eeid, Active Powers, Essay i. ch. v. 

y This last limitation is necessary: the cause, to speak 



PROLEGOMENA LOGICA. 141 

are two distinct positive notions, to which, by dif- 
ferent schools of philosophers, the name cause has 
been ambiguously applied ; the one based on a pre- 
sentation of which we are conscious within our- 
selves, the other on one which we observe without. 
So long as we abide solely by one or the other of 
these, the principle of causality may be understood 
in two distinct senses : either, <f Every fact which 
begins to exist has been produced by an exertion 
of power in a conscious agent," or, " Every fact 
which begins to exist is preceded by some other 
fact or facts with which it is invariably conjoined." 
Or, thirdly, transgressing the limits of either class 
of intuitions separately taken, we may unite the 
two into a negative notion, and assert, " Every fact 
which begins to exist is preceded by another fact 
with power to produce it." 

It is in this last sense, I apprehend, that the 
Principle of Causality is generally admitted as an 
axiom of necessary truth ; those who so admit it 
being perhaps not fully aware of the purely negative 
notion of power, when applied to any other than a 



accurately, is the sum total of the conditions, whose united 
presence is followed invariably by the effect. It is not any 
single phenomenon, unless we can, by successive experiments, 
eliminate all the concomitants save one, and thus shew that, 
as far as the given effect is concerned, they are indifferent. 
This however in practice is seldom the case. On this subject 
some valuable remarks will be found in Mill's Logic, book iii. 
ch. 5. 



142 PROLEGOMENA LOGICA. 

conscious agent 2 ." Thus interpreted, the principle 
in question stands on precisely the same footing as 
that of substance; — an interesting illustration of the 
universal tendency of men to identify, as far as may 
be, other agents with themselves, even where the 
identification tends to the destruction of all clear 
thinking; — furnishing a psychological explanation 
of a form of speech which has prevailed and will 
continue to prevail among all people in all times ; — 
but not properly to be called a necessary truth, 
nor capable of any scientific application ; inasmuch 
as, in any such application, it may be true or false, 
without our being able to determine which, as the 
object of which it treats never comes within the 
reach of our faculties. What is meant by power in 
a fire to melt wax ? How and when is it exerted, 
and in what manner does it come under our cog- 
nisance ? Supposing such power to be suspended 
by an act of Omnipotence, the Supreme Being at 
the same time producing the succession of phe- 



z Thus M. Engel observes, " Dans ce que nous appelons 
force d'attraction, d'affinite, ou meme d'impulsion, la seule 
ehose connue (c'est a-dire representee a l'imagination et aux 
sens), c'est l'effet opere, savoir, le rapprochement des deux 
corps attires et attirant. Aucune langue n'a de mot pour 
exprimer ce je ne sais quoi {effort, tendance, nisus), qui reste 
absolument cache, mais que tous les esprits concoivent neces- 
sairement comme ajoute a la representation phenomenale." 
(See De Biran, Nouvelles Considerations, p. 23.) The ce je ne 
sais quoi expresses exactly the negative character of the notion 
in question. 



PROLEGOMENA LOGICA. 143 

nomena by the immediate interposition of his own 
will, — could we in any way detect the change ? Or 
suppose the course of nature to be governed by a 
pre-established harmony, which ordained that at a 
certain moment fire and wax should be in the 
neighbourhood of each other, that, at the same 
moment, fire by itself should burn, and wax by its 
own laws should melt, neither affecting the other, — 
would not all the perceptible phenomena be pre- 
cisely the same as at present? These suppositions 
may be extravagant, though they are supported by 
some of the most eminent names in philosophy; 
but the mere possibility of making them shews that 
the rival hypothesis is not a necessary truth ; the 
various principles being opposed, only like the 
vortices of Descartes and the gravitation of Newton, 
as more or less plausible methods of accounting 
for the same physical phenomena. 

With regard to the two positive forms of the 
principle : the second, which employs Cause in 
Hume's sense of the term, is no more than an 
induction from experience, and can never at highest 
rise beyond the assertion of a general fact in 
nature. For, when we have divested inanimate 
objects of the negative notion of power, nothing 
remains to distinguish one phenomenon as the 
cause of another, except the characteristic of con- 
stant conjunction with it. Observations and expe- 
riments are instituted for the purpose of determin- 
ing whether, in any given case, the conjunction 



144 PROLEGOMENA LOGICA. 

really is constant or not ; whether two phenomena 
A and B are in fact so related, that nature never 
presents and man never produces a single instance 
of the one without the other. But observation and 
experiment do not presuppose, as an a priori prin- 
ciple, that there must always be some one ante- 
cedent phenomenon of this character, that, out of 
the thousands of cases in which the phenomenon 
B takes place in the course of nature, some one of 
its immediate antecedents must be the same in all. 
Such a conclusion may be established, as a matter 
of fact, by a long course of observation : it may be 
regarded as extremely probable beforehand, from 
what observation teaches us of the uniformity of 
nature in other instances : but in these cases it is 
not a principle of necessary truth ; it is an inductive 
law or general fact in the constitution of nature as 
now established by the will of God. It is thus, 
and it might be otherwise. 

In point of fact, the principle, as thus explained, 
is so far from being necessary, that it has not yet 
been ascertained to be true. As far as observation 
has hitherto gone, the same phenomenon occurs at 
different times with totally different antecedents. 
Thus, as Mr. Mill has observed, one set of observ- 
ations or experiments shews that the sun is a cause 
of heat, another that friction is a cause of it, others 
that percussion, electricity, and chemical action 
are also causes. It is very possible, indeed highly 
probable, that further observation may hereafter 



PROLEGOMENA LOGICA. 145 

discover some one uniform feature running through 
these several sources ; but this is only a probability 
supported by the analogy of nature in other in- 
stances; it is not a necessary law of our own minds 
compelling us, prior to experience, to pronounce 
that a plurality of physical causes is impossible. 

But the physical Law of Causality may be stated 
in a less exceptionable form : " Every phenomenon 
which takes place has, among its immediate ante- 
cedents, some one fact or combination of facts, 
which being repeated, the same phenomenon will 
invariably recur." For though it may be a matter 
of question, whether the same phenomenon may 
not proceed from a variety of physical causes, it 
appears to be beyond all doubt that any one of 
those causes, whenever it takes place, will be 
adequate to the production of the effect. Thus 
expressed, the law in question is identical with that 
belief in the uniformity of nature, which Hume 
endeavours to explain by association, which his 
antagonists of the Scottish school refer to an 
original principle of our nature, while Mr. Mill 
holds it to be itself an instance of induction, and 
induction by no means of the most obvious kind. 

None of these solutions is entirely satisfactory. 
That of Hume has been sufficiently refuted, even 
by the disciple of his general theory, Brown. That 
of an original principle of our nature, though true 
as far as it goes, is too vague, and confounds under 
one general term things which it should be the 

L 



146 PROLEGOMENA LOGICA. 

principal object of any mental classification to dis- 
tinguish. There are some original principles of 
our nature of immutable obligation ; and there are 
others which are perpetually leading us astray. 
There are some which lead us to truths which we 
cannot reverse even in thought ; and there are 
others which point out only contingent and variable 
phenomena. Sight and hearing, appetite and 
desire, the law of conscience, and the intuitions of 
space and time, are all equally original principles 
of our nature ; that is, we can ultimately give no 
account of them, but that it has pleased our Maker 
so to constitute us. Mr. Mill's explanation over- 
looks the fact, that when the principle in question 
is found in apparent conflict with experience, it is 
invariably assumed to be in the right, and expe- 
rience in the wrong ; which is not the case with 
merely inductive laws : to say nothing of the 
paralogism of making the ground and principle of all 
induction itself dependent upon induction, and upon 
induction only. Our earliest and unphilosophical 
inductions appear as often to indicate variety in 
the operations of nature as uniformity. The sun 
rises and sets, the tide ebbs and flows, with regu- 
larity ; but storm and calm, rain and sunshine, 
appear to observe no fixed order of succession. 
But, in any instance whatever of physical causation, 
let an apparent repetition of the cause not be fol- 
lowed by that of the effect ; and all men alike, 
philosophical or unphilosophical, will at once 



PROLEGOMENA LOGICA. 147 

assert that there was some latent variety in the 
circumstances, and not a change in the uniformity 
of their succession. 

At the same time, it is a principle of contingent 
truth only, not of necessary truth, at least, not in 
the highest sense of the term. I can suppose, 
though I cannot conceive, that in some other 
portion of the universe, the phenomena of matter 
may have no settled relations to each other, or 
even no relation at all. Each may be absolutely 
detached from, and independent of, every other; or 
there may be dependencies continually changing, 
so that phenomena at one time and in one place 
connected as cause and effect, may at another 
time or in another place have no connection at 
all. It is true that I cannot conceive such a state 
of things, my intuitions having been exclusively 
conversant with phenomena of a different cha- 
racter ; but I am not warranted in assuming that 
the present limits of my powers of conception are 
the necessary limits of every possible condition of 
things. 

We have thus a remarkable parallel between 
the general law of causation, as applicable to 
physical phenomena, and the psychological facts 
of our own constitution, the reverse of which, as 
was observed at the beginning of the present 
chapter, may be supposed, but cannot be conceived. 
And this parallel, I am inclined to think, furnishes 
a key to the true character of the law. If we 

l2 



148 PROLEGOMENA LOGICA. 

were told of an instance on our own globe, in which 
the repetition of exactly similar phenomena had 
apparently not been followed by the same effect, 
we should without hesitation account for it on one 
of two grounds. Either the phenomena were not 
really exactly similar, or the interposition of some 
intelligent being had prevented the natural result. 
And if we were asked, why these two alternatives 
alone are admissible, we should probably reply, 
" because matter cannot change of itself." Now 
why cannot we think of matter as changing itself? 
Because power, and the origination of change, or 
self-determination, have never been given to us, 
save in one form, that of the actions of the con- 
scious self. What I am to conceive as taking 
place, I must conceive as taking place in the only 
manner of taking place in which it has ever been 
presented to me. This reduces the law of Causality, 
in one sense indeed, to an empirical principle, but 
to an empirical principle of a very peculiar cha- 
racter ; one, namely, in which it is psychologically 
impossible that experience should testify in more 
than one way. Such principles, however empirical 
in their origin, are coextensive in their application 
with the whole domain of thought. They cannot, 
properly speaking, be called inductive truths ; for 
they require no accumulation of physical expe- 
rience. The course of Nature is thought as uni- 
form, because, so long as Nature alone is spoken 
of, that element is absent which alone we can 



PROLEGOMENA LOGICA. 149 

think of as originating a change, Intelligence. 
And for the same reason, so long as the several 
phenomena of Nature are believed to be each 
under the control of a separate intelligence, the 
axiom of her uniformity will admit of perpetual 
modification. The winds may blow north or south, 
as suits the caprices of iEolus ; Xanthus may 
neglect the laws of his periodical rise and fall, to 
arrest the progress of Achilles ; and even the 
steady-going coachman, Phoebus, may alter upon 
occasion the pace of his chariot, to gratify the 
wishes of his roving parent. 

To call the Principle of Causality, as thus ex- 
plained, a Law of Thought, would be incorrect. 
We cannot think the contrary, not because the 
laws of thought forbid us, but because the material 
for thought is wanting. Thought is subject to 
two different modes of restriction : firstly, from 
its own laws, by which it is restricted as to its 
form ; and, secondly, from the laws of intuition, 
by which it is restricted as to its matter. The 
restriction, in the present instance, is of the latter 
kind. We cannot conceive a course of nature 
without uniform succession, as we cannot con- 
ceive a being who sees without eyes or hears 
without ears; because we cannot, under existing 
circumstances, experience the necessary intuition. 
But such things may notwithstanding exist; and, 
under other circumstances, they might become 
objects of possible conception, the laws of the 



150 PROLEGOMENA LOGICA. 

process of conception remaining unaltered. This 
will be more clearly seen hereafter, when we come 
to treat of Logical Necessity and the Laws of 
Thought. 

It remains to say a few words on the other 
interpretation of which the Principle of Causality 
is susceptible : viz. " Every fact which begins to 
exist has been produced by an exertion of power 
in a conscious agent." After the explanation that 
has been given of the former enunciation of the 
principle, the present will be easily seen to be 
correlative to it. The one asserts that we cannot 
conceive matter to change itself; the other asserts 
that all such changes must be referred to mind. 
Both are thus equally contingent, or, in another 
point of view, equally necessary. Both are con- 
tingent, inasmuch as they depend on certain 
existing facts of our constitution and the circum- 
stances in which we are placed,, and we might 
have been constituted or circumstanced otherwise. 
Both are necessary, inasmuch as, while our con- 
stitution and circumstances remain as they are,, 
we cannot but think them. Neither of them 
stands on precisely the same level as mathematical 
demonstration, nor yet on that of the merely con- 
tingent facts of physics. But, with regard to the 
notion of power, as derived from consciousness, 
it is necessary to observe one caution. Our im- 
mediate intuition of power, as has been before 
observed, is to be found in the consciousness of 



PROLEGOMENA LOGICA. 151 

mind as modifying itself, the ego determining its 
own volitions. That mind operates upon matter, 
we are not immediately conscious ; it is not given 
in any intuition that the determination of the will 
acts upon the muscles of the arm, though the 
motion of the latter follows the generation of the 
former. Hence, though we are compelled to 
ascribe all change to the only power of which we 
are conscious, we are unable to ascribe it in the 
only manner of operation of which we are con- 
scious. For purposes of scientific investigation, 
the principle is thus purely negative, though it 
serves to regulate our belief. We know not to 
this day, and we never can know in this life, how 
mind operates upon matter; though we must 
believe that, in some way or other, it does so 
operate. It is impossible, therefore, to construct 
deductively any system of Natural Philosophy 
from the Principle of Causality, or from any other 
axiom expressing the agency of mind upon matter. 
The value of such principles is purely psycho- 
logical. 

From the view above given of the Principle of 
Causality, some important consequences might be 
drawn relatively to other sciences ; which, how- 
ever, my present limits do not permit me to 
attempt. One such remark, however, will, I trust, 
be tolerated, both from the intrinsic importance 
of the question to which it relates, and from its 
connection with the doctrines of an eminent 



152 PROLEGOMENA LOGICA. 

author % to whom I have been considerably in- 
debted in the preceding pages. If the view above 
taken be sound, we are enabled to detect a fun- 
damental fallacy in the argument in favour of 
necessity from the determination of the will by 
motives. If every thing in nature, it is argued, 
must have a cause or sufficient reason, the de- 
terminations of the will cannot be exempted from 
this general law. If I am determined by motives 
in the formation of every act of volition, then 
there is something previous to such act which 
made it to be necessarily produced. If I am not 
so determined, there is an effect in nature without 
a cause. In this argument, there is a latent 
ambiguity of language. As applied to Physics, 
the cause of a phenomenon is a certain antecedent 
fact, which being repeated, the phenomenon will 
recur. This notion of cause is gathered from 
material phenomena, and can only by an imperfect 
analogy be applied to mental. In this sense, 
motives addressed to the will are not causes ; for, 
in every act of volition, I am fully conscious that 
I can at this moment act in either of two ways, 
and that, all the antecedent phenomena being 
precisely the same, I may determine one way 
to-day, and another way to-morrow. To speak 
of the determinations of the will as caused by 
phenomena, in the same sense in which the fusion 

a For the argument of Mr. Mill, here alluded to, see 
Appendix, note C. 



PROLEGOMENA LOGICA. 153 

of metal is caused by fire, is to give the lie to 
consciousness for the sake of theory. On the 
other hand, if cause be interpreted to mean an 
agent with power, my only positive notion of 
cause in this sense is derived from the conscious- 
ness of myself as determining, not as determined. 
Of the power of motives upon my will, conscious- 
ness tells me nothing; but only that the one is 
presented and the other follows ; not, however, 
as in Physics, uniformly. My notion of causes 
with power, other than myself, is derived from the 
primary intuition of myself as a cause, and cannot 
be made to react upon that intuition, without the 
fallacy of deducing the known from the unknown. 
Of myself as necessitated by motives, my imme- 
diate consciousness tells me nothing. It is a mere 
inference from a supposed general law of causality, 
which law is itself derived from the consciousness 
of the very reverse. You are conscious, says the 
necessitarian, of yourself as a determining cause ; 
therefore you must be a determined effect By 
what logic does this follow ? If these consi- 
derations suggest a limit to the universality of the 
principle of sufficient reason, so be it. No prin- 
ciple can consistently be allowed so much uni- 
versality, as to overthrow the intuition from which 
it had its rise \ 

b The above cursory remarks are of course not designed as 
a full examination of the problem of necessity, but only as a 
hint for examining one of the arguments advanced in its 



154 



PROLEGOMENA LOGICA. 



Another observation will not be deemed un- 
important by those who are aware how many 
philosophical theories have been constructed on 
the sole basis of philosophical phraseology . Locke 
has laid some stress on the fact, that the names 
which stand for insensible actions and notions, 
are derived from those of sensible objects. " To 
imagine, apprehend, comprehend, adhere, conceive, 
instil, disgust, disturbance, tranquillity, &c. are all 
words taken from the operations of sensible things, 
and applied to certain modes of thinking. By 
which we may give some kind of guess what kind 
of notions they were, and whence derived, which 
filled their minds who were the first beginners of 
languages : and how nature, even in the naming 
of things, unawares suggested to men the originals 
and principles of all their knowledge d ." The 
fallacy of the theory attached to this fact by 
Locke himself, and by Home Tooke, has been 
fully exposed by Dugald Stewart ; but it should 
also have been observed that, in point of fact, the 



support. More would be out of place here. A few additional 
observations will be found in the Appendix, note D. 

c It will scarcely be credited that a philosopher of Hegel's 
eminence should have connected a logical theory of judgment 
with the fact, that the German word Urtheil etymologically 
means original part. Such a method of philosophizing could 
hardly have been surpassed by Conradus Crambe, or his 
facetious relative, Mr. Swan, Gamester and Punster of the 
City of London. 

d Essay, b. iii. ch. i. §. 5. 



PROLEGOMENA LOGICA. 155 

obligation is not entirely on one side. While, as 
regards attributes and phenomena, the language 
of mental science has mostly been borrowed from 
that of sensation ; in all that relates to the notions 
of cause or force, as has been well remarked by 
Maine de Biran, the language properly belonging 
to the mental fact has been transferred by analogy 
to the physical. As the basis of a theory, the 
fact is of no great value ; but its weight, such as 
it is, should at least be acknowledged to bear on 
both sides of the question. 

Before closing the present remarks, it is necessary 
to say a few words in reference to an objection 
which will probably have frequently suggested 
itself to those conversant with the literature of the 
subject. The origin here assigned to the principle 
of causality, (and the same may in some degree be 
said of that of substance also,) may perhaps appear 
to be of too empirical a character to consist with 
the amount of universality assigned to the principle 
itself; besides being in some respects at variance 
with the opinions of those philosophers to whom 
the preceding pages are mostly indebted 6 . Sir 
William Hamilton has remarked that, if the con- 
ception of active power is derived, as Reid asserts, 
from our voluntary exertions, our notion of causality 
would be of an empirical derivation, and without 

e A point at issue between two eminent French philo- 
sophers, to whose writings I am under considerable obli 
gations, will be considered in the Appendix, note E. 



156 PROLEGOMENA LOGICA. 

the quality of universality and necessity f . Reid 
himself, in another passage, admits the same thing. 
" The proposition to be proved/' he says, " is not a 
contingent but a necessary proposition. It is not 
that things which begin to exist commonly have a 
cause, or even that they always in fact have a 
cause ; but that they must have a cause, and 
cannot begin to exist without a cause. Proposi- 
tions of this kind, from their nature, are incapable 
of proof by induction. Experience informs us only 
of what is or has been, not of what must be ; and 
the conclusion must be of the same nature with 
the premises." 

That experience is the chronological antecedent 
of all our knowledge, even of the most necessary 
truths, is now generally admitted. But a distinc- 
tion is frequently drawn, and has been more than 
once adverted to in the preceding pages, between 
truths or notions of which experience is the source, 
and those of which it is only the occasion. The 
mind, instead of being compared to a tabula rasa, 
on which experience impresses the whole writing, 
is likened to a seed, which must indeed be planted 
before it will grow ; but contact with the soil is 
only the occasion which calls forth the hidden 
germ of the plant. Both analogies are imperfect; 
and both, as regards the present question, tend 

f Reid's Works, p. 604. 

§ Intell. Powers, Essay vi. ch. 6. (p. 455, of Sir W. Hamilton's 
edition.) 



PROLEGOMENA LOGICA. 157 

rather to darken than to illustrate. The point 
may be better explained by laying aside, as far as 
is possible, physical imagery altogether, and by 
examining separately the relation to experience of 
notions or concepts, and of judgments ; instead of 
confounding both under the vague expression, 
origin of ideas. 

Every general concept is in one sense empirical ; 
for every concept must be formed from an intuition, 
and every intuition is experienced. But there are 
some intuitions which, from our constitution and 
position in the world, we cannot help experiencing ; 
and there are others which, according to circum- 
stances, we may experience or not. The former 
will give rise to concepts which, without any great 
impropriety of language, may be called native or 
a priori ; being such as, though not coeval with 
the mind itself, will certainly be formed in every 
man as he grows up, and such as it was preordained 
that every man should have. The latter will give 
rise to concepts which, for a like reason, may be 
called adventitious or d posteriori ; being such as may 
or may not be formed, according to the special 
experience of this or that individual. To the 
former class belong the notions of time and space, 
as implied in all our intuitions, internal or external : 
to this class belong also the notions of seeing, hear- 
ing, and such other mental operations, as, in some 
manner or other, are performed by every man not 
physically deficient in the requisite organs. Of the 



158 PROLEGOMENA LOGICA. 

same kind are the notions of right and wrong, 
which must necessarily arise in the mind of every 
man who has ever performed an action of which 
his conscience approves or disapproves, — and all 
men must at times do both. The numerous con- 
troversies concerning the existence of a moral 
sense may be considerably simplified by this con- 
sideration h . On the other hand, to the class of 
adventitious notions belong those of this or that 
colour, sound, &c. in short, of all simple or com- 
plex objects of perception, which it is possible may 
have been presented to the experience of one man 
and not to that of another. 

But a necessity of which I am conscious, can, 
like truth and falsehood, exist only in judgments. 
It may be ordained by the laws of my constitution 
that I must necessarily form certain notions ; but 
those notions are not therefore thought by me as 
necessary. The simplest form in which necessity 
can be presented to my consciousness is that of a 
judgment, A must be B. This character belongs 
to all such judgments as by the laws of his con- 
stitution a man must form, supposing him to be pos- 
sessed of the constituent concepts. 

There are certain concepts which, whether 
native or adventitious in their own origin, must, 
when once gained, necessarily be thought in con- 
junction : there are others which we are at liberty 
to connect or not, according to circumstances. 
h See Appendix, note F. 



PROLEGOMENA LOGICA. 159 

This necessity or contingency of judgments is 
generally confounded with necessity or contin- 
gency in the corresponding concepts ; but the fact 
is, that they are not even coextensive in their 
provinces. There may be thousands of men who 
never heard of a circle or its radius : there is not 
one who, those notions being once acquired, can 
fail to see that all the radii of a circle must be 
equal to each other. 

Necessity in judgments is dependent sometimes 
on the laws of thought, sometimes on the laws of 
other parts of our constitution ; and the term may, 
in another sense, be applied to that character in 
certain judgments which arises from the limitation 
of our faculties, and from the circumstances in 
which all men alike are placed. Thus by the 
laws of thought, every part of any given concept, 
be its origin what it may, must be thought as 
identical with itself; and hence arises the logical 
necessity of all analytical judgments. By the laws 
of our intuitive faculties, all objects of external 
perception have a certain relation to Space, and 
all objects of internal perception to Time ; and 
hence arises the mathematical necessity of geo- 
metrical and arithmetical judgments. Again, the 
limitations imposed on our intuitive faculties re- 
strict us, in the case of certain intuitions, to one 
relation only between them ; and hence arises the 
psychological necessity of certain judgments, of 
which we can suppose, but cannot conceive, the 



160 PROLEGOMENA LOGICA. 

contrary. The restriction in this case is not 
properly a law regulating acts which we can per- 
form, but a bar separating us from acts which we 
cannot perform. None of these classes of judg- 
ments can properly be termed empirical ; being 
dependent, not on experience alone, but on expe- 
rience in conjunction with certain laws and limit- 
ations of our mental constitution. They are thus, 
to adopt Shaftesbury's correction of Locke, if not 
innate, at least connatural; the constitution of man 
being such, that being adult or grown up, at such 
or such a time, sooner or later, (no matter when,) 
they will infallibly, inevitably, necessarily spring 
up in him. These laws and limitations of our 
constitution render necessary the adoption of 
Leibnitz's addition to the Stoical dogma 1 , " Nihil 
est in intellectu, quod non fuerit in sensu, nisi ipse 
intellectus" And even with this addition, sense 
must be understood with extreme latitude, for every 
possible kind of external or internal presentation. 
There is another class of judgments, in regard to 
which our experience is restricted by the circum- 
stances in which we are universally placed. This 
is the case with the results of existing physical laws 
of the universe, which we can perfectly conceive 
reversed, though within our actual experience they 
never are so. I am fully convinced, for example, 
that, under the existing state of things, a stone 
thrown into the water will sink to the bottom ; 
» Frequently, but erroneously, attributed to Aristotle. 






PROLEGOMENA LOGIC A. 161 

but it is perfectly conceivable that it might float. 
Lastly, there is a class of judgments which are, in 
the strictest sense, contingent ; such as relate to 
the conduct of a voluntary agent, who is subject to 
no necessary restraint, whatever may be his moral 
obligations. 

The above remarks are not designed as an exact 
statement of the theory of any previous philo- 
sopher 1 ', nor as an explanation of language which 
has been hitherto employed in describing a sup- 
posed origin of our ideas. They are offered only 
as expressing what I believe to be a more exact 
and accurate account than is conveyed by the 
physical analogies already mentioned, by the vague 
phraseology of source and occasion, or by the obscure 
notions of potential and actual consciousness. They 
likewise help to distinguish, what it is important to 
keep separate from each other, necessity in the 
acquisition of concepts, and necessity in their com- 
bination in judgments. It is hardly correct, for 
example, to call mathematical notions native, or 
a priori ; since it is by no means necessary or 
universal among mankind to form the concept of 
a circle or a triangle, still less of an ellipse or a 
parabola. But the judgments affirming the pro- 
perties of these figures are necessary in the highest 

k They approach closely to the view given by Maine de 
Biran in his 6th and 7th Answer to the objections of Stapfer; 
but that philosopher has hardly marked with sufficient dis- 
tinctness the positive and negative elements. 

M 



162 PROLEGOMENA LOGICA. 

possible degree. On the other hand, the concep- 
tion of a cause is necessary in its origin ; all men 
being, in some degree, conscious of the exertion of 
power in their voluntary acts. But the necessity 
of the principle of causality, as a proposition, is of 
an inferior degree to that of mathematical judg- 
ments. The general result may be summed up as 
follows. 

1. Judgments necessary in the first degree, or 
logical and mathematical necessity. These are 
dependent on the laws of our mental operations ; 
and their contradictions are neither conceivable 
nor supposable. 

2. Judgments necessary in the second degree, or 
psychological necessity. These are dependent on 
the restrictions of our mental constitution ; and 
their contradictories are supposable, but not con- 
ceivable. To this class belong the principles of 
causality and of substance. 

3. Judgments necessary in the third degree, or 
physical necessity. These are dependent on the 
laws of the material world ; and their contradictories 
are both supposable and conceivable, but never 
actually true. 

4. Judgments purely contingent, where either 
contradictory may be the true or the false alterna- 
tive. Such are all judgments reducible to no law 
of causation. 

To this last class belong at the present moment 
many judgments on physical phenomena; but here 



PROLEGOMENA LOGICA. 163 

the contingency solely arises from our ignorance 
of the law, and may hereafter be removed. Thus 
I am certain that the sun will rise to-morrow; 
but I am uncertain whether the wind will blow 
from the north or south. But this only means 
that we are acquainted with the laws of the one 
phenomenon and ignorant of those of the other. 
The progress of science may raise all these judg- 
ments to cases of physical necessity. But my 
whole consciousness assures me that my own 
voluntary acts are subject to no invariable law, 
and that to dream of any amount of future science 
enabling a man to predict these, as he can now 
predict an eclipse and may hereafter predict a 
change of weather, is perfectly chimerical. These 
last judgments are, therefore, in the strictest sense 
of the term, contingent; while those of the second 
and third class, as before observed, may be called 
contingent or necessary, according to the different 
points of view in which they are regarded. 

It only remains to point out the relation of the 
present chapter to Logical Science. Accidentally, 
it may be applied to the correction of a few per- 
versions of the Scholastic Logic, such as the 
theory of demonstrative syllogisms; but its essential 
connection with the Science will be found in the 
different forms of conceptions and judgments. 
Though the notions of substance and of cause are 
obscure and negative only, the processes of con- 
ception and judgment, in their primitive form, 

m2 



164 PROLEGOMENA LOGICA. 

proceed upon the tacit acknowledgment of the 
existence of something of the kind. In the act 
of conception, for example, different attributes are 
regarded as forming one whole by relation to a 
common substance. My conception of gold, for 
example, is that of a yellow, hard, heavy body : 
but the colour is perceived by the eye, the hard- 
ness is discerned by touch, the weight is made 
known by its pressure as it lies in my hand. 
When I conceive these various attributes as form- 
ing one thing, the gold is neither the colour, nor 
the hardness, nor the weight, but the something 
to which all these qualities belong. Again, having 
conceived gold as yellow, and hard, and heavy, 
I afterwards discover it to be soluble. Here, in 
forming the judgment, gold is soluble, I regard 
the attributes forming the subject and the predi- 
cate as coexisting in a common substance; and this 
identity of substance is expressed by the copula. 
Our ordinary modifications of thought and speech 
thus contain certain negative elements, the notions 
attached to which no amount of reflection or 
analysis can render perfectly clear and distinct; 
though they have been instinctively adopted by 
all mankind, and underlie forms of speech and 
thought which are found among all nations. No 
language can in these respects be constructed 
upon principles of philosophical analysis; for 
analysis cannot take place till language has 
arrived at a certain stage of maturity ; and, till 



PROLEGOMENA LOGIC A. 165 

that period, it must be suffered to grow up with 
all the imperfections consequent on a hasty gene- 
ralization from the data of personal intuition. The 
logical character of these negative notions will be 
more fully explained when we come to examine 
the distinction between the matter and the form 
of thought. 

A preliminary examination of the principles of 
substance and causality is also necessary, before 
we can inquire into the character of the logical 
laws of thought. If it were strictly accurate to 
regard the principle of causality, with M. Cousin \ 
as a Principle of the Reason; — if it were true, that 
one term of the judgment, that of change, being 
given, the mind is competent by its own act to 
add the other, and assert " change supposes a 
cause;" and that this term thus added contains 
a positive element of thought, and not a mere 
negation of the existence of data for thinking ; — if 
this were the case, the whole Science of Logic 
would have to be remodelled accordingly. The 
Reason, as distinguished in Kant's sense from the 
Understanding, would become a source of specu- 
lative truth; its principles would assume the cha- 
racter of Laws of Thought; and Logic would 
become, according to M. Cousin's conception, the 
passage from Psychology to Ontology : the process 
of pure thinking would conduct us to the science 
of pure Being. A Logic of the Reason would thus 

1 Cours de Philosophie, Lecon 19. 



166 PROLEGOMENA LOGIC A. 

become a necessary complement of the Logic of 
the Understanding ; and a considerable portion, if 
not the whole, of the Hegelian Dialectic must be 
incorporated with the Formal Science of Kant. 
To shew that such a treatment, instead of being a 
completion, would be a corruption of the Science, — 
instead of making Logic fruitful of truths, would 
make it prolific of chimeras, — instead of attaining 
knowledge, would aim at impossibilities, has been 
one of the main objects of the preceding inquiry. 



CHAP. VI. 

ON LOGICAL NECESSITY AND THE LAWS OF THOUGUT. 

The result of the two preceding chapters has 
been to mark off two classes of Necessary Truths, 
which, though dependent, as all such truths must 
be, upon mental laws and limitations, do not, pro- 
perly speaking, exhibit the operation of Laws of 
Thought, nor come within the province of Logic. 
We have now to examine the psychological cha- 
racter of the laws of pure thinking, and the kind 
of necessity exhibited in consequence by strictly 
logical processes. The following passage from 
Mr. Mill's Logic may serve to introduce the 
subject. 

" This maxim, (the dictum de omni et nullo,) when 
considered as a principle of reasoning, appears 
united to a system of metaphysics once indeed 
generally received, but which for the last two 
centuries has been considered as finally abandoned, 
though there have not been wanting, in our own 
day, attempts at its revival. So long as what were 
termed Universals were regarded as a peculiar 
kind of substances, having an objective existence 
distinct from the individual objects classed under 



168 PROLEGOMENA LOGICA. 

them, the dictum de omni conveyed an important 
meaning; because it expressed the intercommunity 
of nature, which it was necessary upon that theory 
that we should suppose to exist between those 
general substances and the particular substances 
which were subordinated to them. That every 
thing predicable of the universal was predicable of 
the various individuals contained under it, was 
then no identical proposition, but a statement of 
what was conceived as a fundamental law of the 
universe. The assertion that the entire nature 
and properties of the substantia secunda formed 
part of the properties of each of the individual 
substances called by the same name ; that the 
properties of Man, for example, were properties of 
all men ; was a proposition of real significance 
when Man did not mean all men, but something 
inherent in men, and vastly superior to them in 
dignity. Now, however, when it is known that a 
class, an universal, a genus or species, is not an 
entity per se, but neither more nor less than the 
individual substances themselves which are placed 
in the class, and that there is nothing real in the 
matter except those objects, a common name 
given to them, and common attributes indicated 
by the name ; what, I should be glad to know, do 
we learn by being told, that whatever can be 
affirmed of a class, may be affirmed of every object 
contained in the class ? The class is nothing but 
the objects contained in it : and the dictum de omni 



PROLEGOMENA LOGICA. 169 

merely amounts to the identical proposition, that 
whatever is true of certain objects, is true of each 
of those objects. If all ratiocination were no more 
than the application of this maxim to particular 
cases, the syllogism would indeed be, what it has 
so often been declared to be, solemn trifling. The 
dictum de omni is on a par with another truth, 
which in its time was also reckoned of great im- 
portance, ' Whatever is, is ;' and not to be com- 
pared in point of significance to the cognate 
aphorism, ' It is impossible for the same thing to 
be and not to be;' since this is, at the lowest, 
equivalent to the logical axiom that contradictory 
propositions cannot both be true. To give any 
real meaning to the dictum de omni, we must con- 
sider it not as an axiom but as a definition; we 
must look upon it as intended to explain, in a 
circuitous and paraphrastic manner, the meaning of 
the word class \" 

I quote the above passage from a work of high 
and in many respects of deserved reputation, as a 
remarkable instance of the total misconception of 
the nature and purpose of Logic, arising from that 
erroneous view to which I have before alluded, 
which regards the Aristotelian and the Baconian 
Organon as forming portions of the same system, 
and as subservient to the same end, that of physical 
investigation or the discovery of " fundamental 
laws of the universe." That the deductive method 
a Mill's Logic, vol. i. p. 231. 



170 PROLEGOMENA LOGICA. 

may be advantageously applied to purposes of 
physical inquiry is unquestionable ; and in this 
respect Mr. Mill has certainly not underrated its 
value. Any single proposition of any syllogism or 
chain of syllogisms may thus materially contain a 
fact or a law of nature : but that the fundamental 
principle on which all reasoning is supposed to 
depend can by any possibility exhibit a law of 
external nature and not a law of mind, is a sup- 
position which, if tenable, would make a science of 
Logic impossible. If the dictum de omni were, as 
Mr. Mill supposes, formed on the hypothesis that 
universals had a distinct existence in nature apart 
from the mind that contemplates them, Logic might 
be entitled to rank with Optics or Astronomy, as 
a science of the laws of this or that order of natural 
phenomena ; or it might perhaps aspire to the 
character of a general Cosmology, including these 
and other physical sciences as subordinate branches ; 
but it could not pretend to the slightest knowledge 
of the laws which the mind obeys in thinking ; and 
its principles, as mere generalizations from expe- 
rience, could never attain to more than a physical 
necessity, as the statement of certain facts in the 
existing constitution of the world. 

A science is never ultimately benefitted by dis- 
sembling any conclusion to which its principles 
appear fairly to lead; still less can it gain by 
adulterating those principles themselves with foreign 
matter, borrowed from other departments, in the 



PROLEGOMENA LOGICA. 171 

hope of obviating the apprehended results. In the 
case of Logic especially, it may be confidently 
asserted that nine tenths of the confusion and 
misunderstanding which still prevail concerning 
its nature and capabilities, have arisen from ill 
judged attempts to invest it with an appearance of 
utility in matters alien to its province b . Let us 
therefore look the supposed charge fairly in the 
face, and ask what will be the consequences, if we 
admit that the fundamental principles of pure 
thinking are, as they seem to be, identical or 
analytical judgments. Is Logic thereby deter- 
mined to be false or futile ? By no means. A 
system is futile only when it aims at the solution 
of questions beyond the reach of human faculties : 
and even then, the prosecution of such enquiries 
is attended with an indirect benefit ; inasmuch as 
it is only after repeated failures that men learn to 
know the true limits of their mental powers, and 
can profit by the precept ultimately enjoined by a 
critical psychology : 

" Tecum habita, et noris, quam sit tibi curta supellex." 
It may indeed be humiliating to learn, what such 
an admission necessarily implies, that the under- 
standing of man is not furnished with a power of 
intuition as well as of thought ; but only in the 

b Rosenkranz, in his preface to Kant's Logic, speaks severely 
but truly on this point, " So ist denn auch die Logik hundert- 
fach von philosophischen Stumpern utiliter gemisshandelt 
worden." 



172 PROLEGOMENA LOGICA. 

same way as it is humiliating to know that he 
cannot fly like a bird, nor swim like a fish. The 
restriction is one which the Maker of mankind has 
thought fit to impose upon his creatures ; and, 
regret it as they may, they cannot escape from it. 
If Logic indeed supplied us with nothing but 
identical principles, it would by no means follow 
that the study of it is altogether useless ; but, in 
point of fact, it does very much more. Viewed in 
connection with Psychology, it points to the im- 
portant fact, that these principles are laws of mind : 
and this fact alone, applied to the past history and 
future prospects of Philosophy, will give rise to a 
series of practical rules of inestimable value in the 
direction of the mental powers. 

To prove then that Logic is either futile or 
false, it must be shewn, either that it is impossible 
for a thinking being to attain to a knowledge of 
the laws by which he thinks and to test thereby 
the legitimacy of the products of thought, or that 
the laws by which the human mind is actually 
governed are different from those universally 
assumed and insisted upon by logicians. But if 
on these two points Logic and Psychology are 
found to be at one, each becomes the strongest 
possible guarantee of the truth and scientific value 
of the other. The laws which the logician has 
all along assumed as the basis of his system are 
now shewn to be the very ones by which, from 
the actual constitution of the human mind, the 



PROLEGOMENA LOGICA. 173 

operations of thought are regulated : the con- 
clusions arrived at by a critical examination of 
the mental powers are shewn to be the same laws 
of thinking which had before been accepted as 
principles from a critical examination of the mental 
products. Thus, by the united forces of Logic 
and Psychology, we advance a step in the most 
important of all speculative knowledge, the know- 
ledge of ourselves and of our capacities : and so 
far is either science from being thereby proved 
futile, that they become the strongest possible 
safeguard against all futile speculations, by point- 
ing out clearly the nature of the laws of the pure 
understanding, and the exact limits within which 
they are operative. 

Enough has, I trust, been said to vindicate 
Logic from the charge of frivolity, whatever may 
be the conclusion concerning its principles to 
which our inquiries finally lead us. But in the 
eyes of a philosopher, such a vindication is wholly 
unnecessary. The only question worthy of a 
liberal mind, as regards the result of any investi- 
gation, is not, Is it useful ? but, Is it true ? How- 
ever fully persuaded we may be that every specu- 
lative truth has its practical advantages, to require 
a foresight of such advantages before entering on 
the inquiry is to interpose the most effectual bar 
that can be devised to the progress of any know- 
ledge, and the attainment of any benefit . The 

= This is indeed admitted and ably maintained by some of 



174 PROLEGOMENA LOGICA. 

only tenable position that can be occupied by the 
assailants of Logic must be acquired by shewing 



that class of writers, whose researches are most to the taste of 
the Utilitarian. I am happy to he ahle to quote the following 
admirable vindication of the pursuit of truth for its own 
sake, from a philosopher with whose general principles I am 
by no means inclined to sympathize. 

" Si la puissance preponderate de notre organisation ne 
corrigeait, meme involontairement, dans l'esprit des savans, 
ce qu'il y a sous ce rapport d'incomplet et d'etroit dans la 
tendance generale de notre epoque, rintelligence humaine, 
reduite a ne s'occuper que de recherches susceptibles d'une 
utilite pratique immediate, se trouverait par cela seul, comme 
l'a tres-justement remarque Condorcet, tout-a-fait arretee dans 
ses progres, meme a l'egard de ces applications auxquelles on 
aurait imprudemment sacrifie les travaux purement specu- 
latifs ; car, les applications les plus importantes derivent con- 
stamment de theories formees dans une simple intention 
scientifique, et qui souvent ont ete cultivees pendant plusieurs 
siecles sans produire aucun resultat pratique. On en peut 
citer un exemple bien remarquable dans les belles specu- 
lations des geometres grecs sur les sections coniques, qui, 
apres une longue suite de generations, ont servi, en de- 
terminant la renovation de 1'astronomie, a conduire finale- 
ment l'art de la navigation an degre de perfectionnement 
qu'il a atteint dans ces derniers temps, et auquel il ne serait 
jamais parvenu sans les travaux si purement theoriques 
d'Archimede et d'Apollonius ; tellement que Condorcet a pu 
dire avec raison a cet egard : ' le matelot, qu'une exacte 
observation de la longitude preserve du naufrage, doit la vie 
a une theorie concue, deux mille ans auparavant, par des 
homines de genie qui avaient en vue de simples speculations 
geometriques.' " Comte, Cours de Philosophie Positive, vol i. 
p. 64. 

An English philosopher, who has treated of the same 
subjects in a very different spirit, has expressed the same 



PROLEGOMENA LOGICA. 175 

that men do not, as a matter of fact, reason 
consciously or unconsciously according to its rules; 
that the thinking process is not governed by laws 
at all ; or that its laws are totally different from 
those which the logician lays down. 

But it is time to examine the question itself 
which has given rise to these observations. Are 
the Laws of Thought in reality identical judg- 
ments or not? It may perhaps appear that the 
so-called frivolity of such judgments is the result 
of unsuspected causes, having their root in the 
nature of the mind itself; that the very feature 
which is selected as the especial object of contempt 
and ridicule is the strongest evidence of the truth 
and value of the principles which it characterizes. 
Supposing, then, that the act of thinking is governed 
by certain laws, what might we naturally expect 
to find as the prominent feature by which such 
laws will be distinguished ? A new truth is in its 
very nature partial : it is new only because it is 
partial ;— the discovery of the particular attributes 
of some particular thing or class of things. In a 
psychological point of view, the determination of 
the laws of thought, (be their character as judg- 
ments what it may,) is as much a new truth 
as any other ; being the discovery of a particular 
fact in the constitution of the human mind. But 

sentiment briefly and well. " It may be universally true, 
that Knowledge is Power ; but we have to do with it not as 
Power, but as Knowledge." 



176 PROLEGOMENA LOGICA, 

when we consider the same laws logically, in their 
application to the products of thought, how is it 
possible for any new truth to be determined by 
them ? As general laws, they can have no special 
relation to this object of thought rather than that; 
and it is upon such special relations that the 
discovery of every new property must depend. 
Material knowledge arises from the observation 
of differences : the essential feature of laws of 
thought must be the abstraction from all differ- 
ences' 1 . A necessary law of all thinking, which 
shall at the same time ascertain the definite pro- 
perties of a definite class of things, is a contra- 
diction in terms ; for it is optional, and therefore 
contingent, whether we shall apply our thoughts 
to that particular class of things or not. But if 
all men have been thinking, some on this thing, 
some on that, but all under one code of laws, what 
marvel if, when their attention is called to those 
laws, they should recognise them as what they 
have all along virtually acknowledged ? Herein 
lies at once the explanation and the justification 
of the so-called frivolity of principles of this kind. 
They can determine only the general attributes 
common to all objects of thought as such; and 
these attributes must constitute the very ana- 
lytical judgments which Logic is so much decried 
for offering. Surely, in the name of common 
sense and common honesty, never was outcry 
d Kant, Logik, Einleitung, vii. p. 219. Ed. Kosenkranz. 



PROLEGOMENA LOGICA. 



177 



more absurd than that which finds fault with a 
science for accomplishing the very purpose which 
it professes to attempt, and for exhibiting the very 
features which, if its pretensions are well-founded 
and its method sound, it necessarily must exhibit. 

It is a remarkable fact in the modern history of 
philosophy, as regards identical judgments, that, 
while English philosophers, taking their departure 
from the principles of Locke, have been unsparing 
in their expressions of scorn and censure of them 
as mere verbal trifling, German philosophers, 
taking their departure from the principles of Kant, 
have placed them at the head of all philosophy, 
as the only absolute principles of truth and 
certainty. Yet Kant, as well as Locke, and with 
far more accuracy of discrimination, perceived and 
pointed out the impossibility of constructing a 
system of philosophy upon these judgments only. 
That both extremes are equally in error, — that both 
arise from a crude and one-sided view of a philo- 
sophy not perhaps in all respects consistent with 
itself, — and that the truth lies between the two, is 
a natural and obvious conclusion. To enter into 
the extravagancies of Fichte and Schelling would 
be foreign to the purposes of the present work ; 
but as regards the disciple of Locke, it may be 
observed, that he has no choice but of two 
alternatives ; either to repudiate the attack of his 
master on frivolous propositions, or to retract his 
refutation of the doctrine of innate ideas. If the 



178 



PROLEGOMENA LOGICA. 



principles of thought are competent to supply any 
positive addition to what is given in intuition, it 
follows that the act of thought can in so far 
create its own materials : this brings us back of 
necessity to the theory of innate ideas. If, on 
the other hand, the understanding can only modify 
what is given out of the act of thought, it follows 
that analytical judgments are not mere verbal 
frivolities, but fundamental laws of the thinking 
faculty. 

The Laws of Thought, properly so called, may 
thus be psychologically distinguished from the 
other elements of the process, by the answers to 
the following questions: 1. What is the material 
which must be given prior to any act of pure 
thinking ? 2. How is that material modified by 
the act of thought itself ? 3. What are the 
conditions by which the understanding is bound 
in such modification ? The third question will 
determine the fundamental laws of the several 
operations of Conception, Judgment, and Rea- 
soning. 

The act of conception consists in regarding 
certain attributes as coexisting in a possible object 
of intuition. It has before been remarked, that 
when the object of intuition is actual, i. e. now 
and here present, an act of thought is necessary 
to distinguish it as such from other objects simul- 
taneously presented. This, however, is not pure 
conception, but conception in conjunction with 



PROLEGOMENA LOGICA . 179 

intuition. In pure conception, the attributes are 
not presented in themselves, but represented by 
their signs. Hence the necessity, in some form 
or other, of language ; and hence the object of 
intuition, in an act of pure conception, is not pre- 
sented as actual, but represented as possible d . 

Two preliminary conditions are thus requisite, 
prior to any act of pure conception. Firstly, 
attributes must be given, which in some com- 
bination or other have been presented in a former 
intuition. For, as thought cannot create intuition, 
attributes which have never been experienced are 
not conceivable. They need not indeed have 
been experienced in their present relation, but 
in some relation or other. I may conceive a 
centaur : but both the horse's body and the man'* 
head have been presented in other combinations. 
Secondly, as the attributes are now given in and 
through their signs, the import of those signs is 
presupposed to be known. A word which I 
cannot connect with some known attribute is, for 
all purposes of thought, like the terms of an 
unknown tongue. Pure thought can neither 
supply defects in the experience of things, nor 
ignorance of the meaning of words. Information 
on both these points is therefore presupposed. 

These materials being given, how are they dealt 
with by the act of thought, and what are the 
laws and limits which govern or confine the 

d Cf. Krug, Logik, §.15. 

n2 



180 PROLEGOMENA LOGICA. 

operation ? By the act of conception, the given 
attributes are combined in an unity of repre- 
sentation. Are there then any cases in which, 
certain attributes being given, I am compelled to 
think them as representing an object ? are there 
any cases in which I am forbidden to do so ? and 
are there any in which, as far as thought is con- 
cerned, I am left at liberty to do as I please ? 
Pure conception being concerned with possible 
objects of intuition only, the first and third cases 
merge into one. The actual existence of any 
object can be determined only by its actual pre- 
sence in this or that intuition ; and even then the 
evidence extends only to its present existence now 
and here, not to its necessary existence at any 
future time when it may become an object of 
thought. As an object of a past intuition, it has 
then a possible and representative existence only 6 . 
The first law of pure thinking applicable to con- 
ception is thus indicated by the negative criterion^ 
that there are certain attributes which we cannot 



e " As not now present in time, an immediate knowledge of 
the past is impossible. The past is only mediately cognisable 
in and through a present modification relative to and repre- 
sentative of it, as having been. To speak of an immediate 
knowledge of the past involves a contradiction in adjecto* 
For to know the past immediately, it must be known in itself; 
and to be known in itself, it must be known as now existing. 
But the past is just a negation of the now existent: its very 
notion therefore excludes the possibility of its being imme- 
diately known." Sir W. Hamilton, BeicVs Works, p. 810. 



PROLEGOMENA LOGICA. 181 

think as coexisting in any possible object of in- 
tuition. This leads us to the well-known Principle 
of Contradiction f , the most general form of which 
is, " Nothing can be A and not-A," or, " No object 
can be thought under contradictory attributes." 
But, though every thing which is contradictory is 
thus inconceivable, it cannot be maintained, on the 
other hand, that every thing which is not contra- 
dictory is conceivable g . 

One Law of Thought we have seen to arise from 
the relation of conception to given attributes. 
Another arises from its relation to possible objects 
of intuition. For intuition is possible only under 
the condition of limitation by differences. An 
object of intuition, as such, possesses definite 
characteristics by which it is marked off and dis- 
tinguished from all others : otherwise, it would not 
be an object, but the universe of all objects. In 
the act of conception, therefore, when we regard 
certain given attributes as constituting an object, 
we conceive it as thereby limited and separated 
from all other objects, as being itself and nothing 
else. The indefinite ideas, therefore, corresponding 
to the general terms, Thing, Object, Being in 
general, are not concepts, as containing no dis- 
tinctive attributes ; and the general object denoted 

f This law, as Krug has remarked, (Logik, §. 18.) ought 
rather to be called the Principle of Non-Contradiction. 

6 On conceivability, as a test of logical possibility, see Sir 
W. Hamilton, Reid's Works, p. 377. 



182 PROLEGOMENA LOGICA. 

by such terms is inconceivable. This second Law 
of Thought is expressed by the Principle of 
Identity, " Every A is A," or " Every object of 
thought is conceived as itself \" 

Another limitation must be noticed, which, 
though perhaps not properly an a priori law 
arising out of the nature of thought itself, is at 
least an universally valid a posteriori restriction 
arising from the practical limits of our intuitive 
powers. Thought can only deal with such at- 
tributes as have been in some manner presented 
in intuition. Hence in all cases where intuition 
is impossible, thought is impossible likewise. Hence 
arises a class of practical limitations of thought 
based on the limitations of possible experience. 
Some of these are partial and accidental only ; as 
in the case of a blind man, who can have no 
intuitive experience of colours. But one at least 
is common to all men, and, so far, psychologically, 
if not logically, necessary. Though, as far as the 
laws of thought are concerned, it is permitted to 
unite in an act of conception all attributes which 

h Cf. Krug, Logik, §.17. who contemplates the principle 
from the opposite side. He is wrong however in deducing 
from it the principle of Contradiction, which is an inde- 
pendent axiom. The two have been confounded or identified 
by many eminent Philosophers; as Leibnitz, Reflex, sur Locke, 
Wolf, Ph. Rat. §.271. Kant, Logik, Einl. vii. Herbart, Einl. in 
die Philosuphie, §. 39. HofTbauer, Logik, §.23. shews that the 
two principles are independent, and that neither can be 
deduced from the other without a petitio principii. 



PROLEGOMENA LOGICA. 183 

are not contradictory of each other, it is impossible 
in practice to go beyond a very limited number. 
The number oi attributes in the universe not 
logically repugnant to each other is infinite ; and 
the mind can therefore find no absolute limits to its 
downward progress in the formation of subordinate 
notions. To arrive at a notion which shall com- 
prehend within itself all conceivable compatible 
attributes, which shall admit of no further possible 
limitation but that of the individual conditions of 
presence in space and time, is an act which, if not 
a priori self-destructive, will at least in practice 
require an infinite grasp of mind and an infinite 
length of time for its accomplishment \ 

Hence it follows at once, that a logical Highest 
Genus and a logical Lowest Species, i. e. a notion 
so simple as to admit of no further subtraction, 
and a notion so complex as to admit of no further 
addition, are both inconceivable. The meaning of 
these two terms in Logic must not be confounded 
with that which is applicable to this or that branch 
of material science. The Highest Genus in any 

' This and the preceding condition are sometimes given as 
the Laws of Homogeneity and Specification. See Kant, Kritik 
der r. V. p. 510. ed. Kosenkranz. Krug, Logik, §. 45. b. Fries, 
Syst. der Logik, §.21. I prefer to regard them as deductions 
from a higher law. It may be observed, that those logicians 
who insist on the Law of Homogeneity are not consistent in 
calling thing or object a concept. (Begriff.) The third law 
joined with these two, that of Logical Affinity, or Continuity, is 
questionable, both as regards truth and value. 



184 PROLEGOMENA LOGICA. 

special science is the general class,, comprehending 
all the objects whose properties that science in- 
vestigates : the different Lowest Species are the 
classes at which that special investigation termi- 
nates. In Geometry, for example, under the 
summum genus of magnitudes in space, we find 
three coordinate infimce species of triangles, the 
equilateral, the isosceles, and the scalene. The 
Geometrical properties of the figures are not 
affected by any further subdivision. These three 
classes are therefore lowest species in Geometry, 
but not in Logic. For of geometrical limitations, 
the logician, as such, knows nothing. In a mere 
relation of concepts, the notion of an equilateral 
triangle whose sides are three feet long, is a 
further subdivision of the notion of an equilateral 
triangle ; and out of this again we may form the 
subordinate notion, " an equilateral triangle whose 
sides are three feet long and divided into inches." 
This process may, as far as Logic is concerned, be 
continued ad infinitum. 

The extreme limits of generalization and speci- 
fication being thus inconceivable, we obtain from 
these conditions two characteristics of ail logical 
concepts, namely, that they must have both com- 
prehension and extension. Every notion, that is 
to say, as a condition of its conceivability, must 
contain a plurality of attributes, in consequence 
of which it is capable of subordination to a higher 
notion : and it must contain a limited number only 



PROLEGOMENA LOGICA. 185 

of attributes, in consequence of which lower notions 
may be subordinated to it. This canon of con- 
ceivability, as we have seen, is not invalidated by 
the supposed highest and lowest classes of the 
logicians, which are limits never arrived at in any 
process of actual thought. Neither is it invalidated 
by the so-called simple ideas, which, according to 
the doctrine of Descartes and Locke, are the limits 
beyond which analysis is impossible. For a simple 
idea, like a summum genus, is by itself incon- 
ceivable. In every intuition it is presented as 
part of a complex object ; and it can in no act 
of positive thought be contemplated out of that 
connexion. Whiteness and redness, for example, 
are given to us in combination with extension : 
motion, with a moving body : pleasure and pain, 
with a conscious subject. We cannot represent 
to ourselves, as a possible object of intuition, a 
colour unextended k , a motion without a moving 
body, a feeling without a mind. Simple ideas are 
thus never conceived as such, but only as forming 
parts of a complex object. That they are inde- 
finable, (in Locke's view of definition,) has been 
remarked in a former chapter ; but this arises, not 
from their forming absolutely simple concepts, but 
from then;, being simple portions of a complex 
intuition. 

k The error of those philosophers who suppose that colour 
can be conceived apart from extension, has been noticed by 
Sir W. Hamilton, Beid's Works, p. 860. 



186 PROLEGOMENA LOGICA. 

From these two characteristics of all concepts 
follows their capability of Definition and Division : 
the former being an enumeration of the higher 
notions contained in the comprehension of a given 
concept ; the latter, an enumeration of the lower 
notions contained in its extension. The manner 
however in which these two operations are com- 
monly treated in logical writings manifests an utter 
confusion between the general laws of thinking as 
applicable to any matter, such as they are laid 
down in pure Logic, and the performance of a 
special act of thought about this or that matter, 
which forms a portion of this or that branch of 
applied Logic. The so-called Logical Laws of 
Definition and Division are merely derived from an 
analysis of the notions of the operations them- 
selves ; — notions such as might be borrowed con- 
cerning any object from the art or science to 
which it materially belongs. In the given notion 
of Definition, as the enumeration of the parts com- 
prehended in a concept, it is of course implied 
that it must be adequate ; otherwise the parts are 
not enumerated ; and that it is clearer ; otherwise 
they are not parts. And so of Division, substituting 
parts of extension for those of comprehension. 
Such an analysis furnishes no test even of the 
formal validity of any single act of division or 
definition ; it only takes to pieces the general 
notion of the process. But it is obvious that 
any given notion, borrowed from any source what- 



PROLEGOMENA LOGICA. 187 

ever, may be analysed in like manner by an appli- 
cation of thought. From the notion of weighing 
a pound of cheese, it follows of course, firstly, that 
the whole quantity weighed must be exactly a 
pound ; secondly, that any part of the same must 
be less than a pound ; thirdly, that the same ounce 
must not be weighed twice over. If this criterion 
be adopted, a chapter on cheese-weighing has as 
good a right to be placed in Logic, as a chapter on 
Division or Definition. 

The question necessary to determine the true 
logical character of these processes is not, " Given 
the general notions of the two operations, to deter- 
mine by analysis what those notions imply ;" but, 
" Given any particular concept, how much can be 
ascertained by pure thinking concerning its relation 
to higher or lower concepts ?" Viewed in this 
light, Definition, as a logical operation, is a portion 
of the act of Conception, governed by the same 
laws, and subject to the same limitations. We can 
determine thereby nothing concerning the actual 
possession of certain attributes by certain objects : 
we cannot even ascertain that objects of any kind 
really exist in nature. Conception being limited 
to possible objects of intuition only, Definition is 
confined to the analysis and separate exposition of 
the attributes contained in a given concept, and 
determines not their reality but their conceivability. 
Its only logical law is the Principle of Contradiction : 
a definition which enumerates attributes directly 



188 PROLEGOMENA LOGICA. 

or by implication incompatible with each other, 
is logically self-destructive. If the attributes are 
compatible, the definition is allowed as valid, as 
far as Logic is qualified to pronounce judgment : 
for further examination, it must be referred to the 
tribunal of experience. The purpose of logical 
definition is thus, not material accuracy, but formal 
distinctness as regards the intension or comprehen- 
sion 1 of the concept. 

It is obvious that the rules of definition com- 
monly given in logical treatises have no value or 
significance except in extralogical applications. 
To say that a definition must be adequate to the 
notion which I entertain, is only to say that what I 
assign as the contents of a notion must be what I 
think to be the contents : which is of course im- 
plied in the fact of my assigning them. The rule 
acquires a material significance, when interpreted 
to mean that the attributes assigned in the definition 
must exactly correspond to the characteristic 
features of the object as it exists in nature. But 
then to determine whether this rule is complied 
with or not is clearly beyond the province of the 
logician. I may assign " rational animal," as an 
analysis of my notion of man : but to ascertain, as 
a matter of fact, that all men possess reason, and 
that all other animals are without it, is manifestly 

1 See Drobisch, Neue Darstellung cler Logik, §. 102. 
That analytical distinctness alone falls within the province of 
Logic is shewn by Kant, Logik, Einl. viii. 



PROLEGOMENA LOGTOA. 189 

a question not of thought, but of experience, 
There is no alternative between exempting the 
logician as such from all material knowledge what- 
ever, and requiring from him a minute acquaint- 
ance with every possible branch of human know- 
ledge. If he is bound to know, as a matter of fact, 
that men are rational and horses hinnible, he is by 
the same rule bound to be conversant with the 
nature and properties of every object which nature 
can present or art produce. 

It is obvious also that Logic can admit one kind 
of definition, and one only. The so-called nominal 
definition by synonym or etymology would require 
of the logician a material knowledge of the voca- 
bulary and construction of any given language : 
thus making Logic a compendium of all dictionaries 
and all grammars m . The so-called accidental 



m " In this place," says Archbishop Whately, " we are 
concerned with nominal definitions only, because all that is 
requisite for the purposes of reasoning (which is the proper 
province of Logic) is, that a term shall not be used in different 
smses: a real definition of any thing belongs to the science or 
system which is employed about that thing." In the sense 
in which nominal and real definition were distinguished by 
the scholastic logicians, the exact reverse is the truth. Logic 
is concerned with real, i. e. with notional definitions only : to 
explain the meaning of particular words belongs to the 
dictionaries or grammars of particular languages. But this 
is only one out of thousands of errors committed by various 
writers, through confounding the tiling or notion in the mind 
with the things or individuals out of it. Even Kant (Logik, 
§. 106.) has not quite avoided this ambiguity. 



190 PROLEGOMENA LOGICA. 

definition is a logical absurdity. If the notion 
homo, for example, is composed of the notions 
animal rationale, it cannot at the same time contain 
the distinct attributes of bipes implume. To use 
the same word for both combinations is simply to 
employ language equivocally. It may so happen 
that all the individuals possessed of reason are also 
provided with two legs and destitute of feathers ; 
but this is not implied in the notion of rationality, 
and cannot be elicited by any act of pure thinking. 
For this reason those logicians are clearly right 
who consider the enumeration of properties or 
accidents, not as a definition of notions, but as a 
description of individuals. But such a description 
has clearly no connection with Logic, but solely 
with the natural history of the object described. 

Division, on the other hand, corresponds in one 
sense to the remaining portion of the act of Con- 
ception, the union of the attributes in a possible 
object of intuition, and is thus regulated by the 
Principle of Identity. But Division, in this sense 
of the term, is not Specification, but Individualiz- 
ation; and moreover pays no attention to any 
coordinate members of the same class, but is solely 
occupied with the one object conceived. It is 
impossible for me to conceive a triangle which 
shall be neither equilateral, isosceles, nor scalene : 
one of these attributes therefore enters into every 
actual conception of a triangle, and thus far limits 
and divides the general notion. But then the 



PROLEGOMENA LOGICA. 191 

attributes added are not in this case contemplated 
as the constituents of a lower class, but of a possible 
individual. In like manner, I cannot conceive a 
man of no colour and no stature ; but in adding 
these particulars to my conception, I do not think 
of them as related to any coordinate class, as con- 
stituting a division of men into tall and short, or 
white and not white. I think of them only as 
necessary to the conceivability of the generic attri- 
butes with which they are combined. The office 
of Division in this respect is to make our concep- 
tions clear, as that of Definition is to make them 
distinct 11 . 

Beyond this, the process of Division, as con- 
tributing to distinctness in the extension of a Con- 
cept, cannot be regarded as an act of pure thinking , 
or as solely determined by logical laws. Even in 
the case of dichotomy by contradiction, the prin- 
ciple of division must be given, as an addition to 
the attributes comprehended in the concept, before 

n A conception is clear, when its object, as a whole, can be 
distinguished from any other ; it is distinct when its several 
constituent parts can be distinguished from each other. The 
merit -of first pointing out these characteristics of the logical 
perfection of thought belongs to Leibnitz. See his Medita- 
tiones de Cognitione Veritate et Ideis. 

° By pure thinking, is not meant thinking which has no 
relation to any past experience ; for without some experience, 
all thought is impossible. It means only, that we can proceed 
to the act of thought without additional data being required 
prior to and out of the act itself. The relation of experience 
to thought is too often lost sight of in the Kantian Philosophy. 



192 PROLEGOMENA LOGICA. 

the logician can take a single step. For Division 
is not, like Definition, a mental analysis of given 
materials : the specific difference must be added 
to the given attributes of the genus ; and to gain 
this additional material, it is necessary to go out 
of the act of thought, to seek for new empirical 
data. " Divide animal" is a command which no 
logician as such can obey ; for the mere notion 
animal does not of itself suggest rational or irra- 
tional, any more than mortal or immortal, virtuous 
or vicious, or any other attributes not logically 
incompatible with the genus p . The principle of 
division must be given in addition to the concept 
to be divided ; and when it is given, the process 
thus raised from a material to a formal one has, 
like definition, a potential only, not an actual 
value in relation to experience. If the differentia 
rational is given, I can divide animal into rational 
and not-rational ; but if the differentia mortal is 
given, I can also, as far as Logic is concerned, 
divide into mortal and immortal. I must appeal 
to experience, and not to thought, to determine 
whether one or the other of these divisions is 
actually true, whether the Struldbrugs of Luggnagg 
or the Undying Fish of Bowscale Tarn are really 
existing animals or not. Every concept is poten- 
tially divisible by any two given differentiae, con- 
tradictory of each other, and both compatible with 
the genus. And the laws by which the process is 
p See Fries, System der Logik, §. 92. 



PROLEGOMENA LOGICA. 193 

governed, are, firstly, the Principle of Contradiction, 
and, secondly, that of Excluded Middle. By the 
first, we are forbidden to think that two con- 
tradictory attributes can both be present in the 
same object : by the second, we are forbidden to 
think that both can be absent. The first tells us 
that both differentiae must be compatible with the 
genus : I cannot, for example, divide animal into 
animate and inanimate. The second tells us that 
one or the other must be found in every member 
of the genus : but in what manner this is actually 
carried out, whether by every existing member 
possessing one of the differentiae and none the 
other, or by some possessing one and some the 
other, experience alone can determine q . 

It thus appears that even dichotomy by con- 
tradiction is not, strictly speaking, a formal process, 
as Kant considers it r ; but that it is partly material, 
and so far extralogical ; and that the material 
element predominates still more, according as any 
other principle of division is adopted. Where the 
specific differences are not contradictory, so that 
each naturally suggests the other, every one of 
them must be given, prior to any possible act of 
formal thinking. The only division of a concept 
which can be regarded as a purely logical process 
is that sometimes distinguished as Determination, 

i Trendelenburg, Logische Untersuchungen, i. 4. 
r Logik, §. 113. See on the other side, Hoffbauer, Logik, 
§. 134, 138. 

O 



194 PROLEGOMENA LOGIC A. 

which consists in the reunion of attributes pre- 
viously separated by definition 8 . In a formal point 
of view, therefore, the arrangement of those logi- 
cians who treat of Definition before Division is 
preferable to the inverse order adopted by Aldrich, 
Divisionem excipit Definitio. 

Throughout the preceding remarks, the presence 
of all the antecedent conditions requisite to the 
logical perfection of cognitions is presupposed. It 
is taken for granted that we are, prior to any act 
of conception, in possession of the materials neces- 
sary to complete clearness and distinctness; and 
that the act of thought consists merely in eliciting 
the concept with these qualities out of the sufficient 
data. And this supposition is the only one which 
can be admitted into a system of pure Logic, or 
into Psychology in its purely logical relation. The 
failure of materials for conception is precisely 
analogous to the failure of materials for reasoning. 
In the latter case, if a single premise only is given, 
or two premises so related that no necessary con- 
clusion follows from them, the logician is not called 
upon to remedy the deficiency ; he simply decides 
that the data are insufficient for reasoning at all. 
In like manner, if the empirical data for clear or 
distinct conception are wanting, the logician, as 
such, can only say that the materials for the thought 
are insufficient. The distinction between clear and 
obscure, distinct and indistinct conceptions, is as 
■ See Drobisch, §.17, 29, 30. 



PROLEGOMENA LOGICA. 195 

much out of the province of pure Logic, as a dis- 
tinction between syllogisms whose premises neces- 
sitate their conclusion, and reasonings in which the 
consequence may with more or less probability be 
conjectured. In conception and in judgment, as 
well as in reasoning, there are processes necessitated 
by the laws of thought from certain data ; there are 
others which are not necessitated, but which may 
be hazarded with more or less risk of error ; the pre* 
sumption in their favour amounting in some cases 
to a moral certainty, and binding upon our practice, 
but never reaching the height of logical necessity 
or speculative perfection*. The first class alone 
are recognised by Pure Logic, and that in relation 
not merely to reasoning, but to all three operations 
of thought. Applied Logic, in the Kantian sense 
of the term, may treat of the several practical 
imperfections of human thought, which lower in 
this or that special instance the logical standard of 
perfection. Here we may treat of notions more 
or less obscure or confused, of judgments more or 
less uncertain, of reasonings more or less incon- 
sequent. The object of the present observations 
is rather to ascertain what light may be thrown by 
psychological considerations on the purely logical 
processes, and to call attention to the fact, that the 
distinction between material and formal thinking 
may and ought to be consistently carried out in 
reference to all the operations of the understanding. 

e Cf. Krag, Logik, §. 35. Anm. I. 

o 2 



196 



PROLEGOMENA LOGICA* 



Judgment is distinguished from Conception by 
the difference of its data. In Conception, attributes 
are given, to be united by thought in a possible 
object of intuition : in Judgment, concepts are 
given, to be united by thought in a common object. 
Like Conception also, Judgment may be considered 
either as pure, or as combined with a present in- 
tuition. The latter, however, does not fall within 
the province of Logic, not being an act of pure 
thinking. The logical character and laws of Judg- 
ment may be determined in the same manner as 
those of Conception, by the following question. 
Two concepts being given, what can we determine, 
by an act of thought only, concerning their relation 
to a common object ? In thought, objects are 
known only through the medium of concepts. It 
is manifest therefore, that the only relations which 
pure thinking can determine, must be such as are 
implied in the concepts themselves, not such as 
may objectively exist between concepts totally 
distinct from each other. Analytical judgments 
are thus the only ones which can be regarded as 
the results of a logical process in accordance with 
laws of thought. Synthetical judgments may or 
may not be true, — the supposed relation to a com- 
mon object may or may not exist ; but, inasmuch 
as, without an appeal to experience, the affirmative 
and negative sides of the question are equally 
balanced, such judgments are to pure thinking 
perfectly indifferent. 



PROLEGOMENA LOGICA. 197 

We thus find that logical Judgment, like logical 
Conception, is governed by the Principles of Identity 
and Contradiction. All affirmative analytical judg- 
ments depend on the former ; all negative ones, 
on the latter*. If the two given concepts are so 
related, that the comprehension of the one is 
identical with the whole or a part of that of the 
other, Thought, by the Law of Identity, affirms their 
necessary relation to a common object. If any 
attribute comprehended in the one is contradictory 
of any comprehended in the other, Thought, by 
the Law of Contradiction, denies that such relation 
is possible. But if the contents of the two con- 
cepts are totally distinct, the question of their 
relation to each other is taken out of the province 
of thought, and falls within that of experience u . 

Another law of thought is sometimes given as 
the foundation of Judgment, under the name of 
the Logical Principle of Sufficient Reason. This 
law, which must be carefully distinguished from the 

t " In propositione identica subjecto et praedicato eadem 
respondet notio; consequenter eadem utroque res indicatur. 
Propositio igitur identica generalis, quae caeteras omnes am- 
bitu suo complectitur, hsec est: Idem ens est ilhid ipsum ens, 
quad est, seu Omne A est A, ubi A denotat generatim ens 
cujuscunque speciei vel generis, sive in communi, sive in 
singulari." Wolf, Phil. Bat. §. 270. 

u Drobisch, §. 36. refers synthetical as well as analytical 
judgments to the principle of identity. But in relation to 
the former, Logic can only determine the possibility of their 
truth, which implies an equal possibility of their falsehood : 
i. e. Logic is incompetent to determine any thing about thenu 



198 PROLEGOMENA LOGICA. 

Metaphysical Principle of Causality, is enunciated, 
" Every judgment must have a sufficient ground 
for its assertion \" But, in truth, the relation of 
this principle to the act of judgment is merely 
negative : it forbids us in certain cases to judge at 
all, and it does no more. If the judgment is 
analytical, the law of Identity or of Contradiction 
is the sufficient reason for making it. If the judg- 
ment is synthetical, we have, as far as thought is 
concerned, no reason at all ; and, accordingly, we 
refer the decision to the tribunal of experience. 
The only logical reason for a thought of any kind 
is its relation to some other thought : and this 
relation will in each case be determined by its own 
proper law. The Principle of Sufficient Reason is 
therefore no law of thought, but only the statement 
that every act of thought must be governed by 
some law or other 7 . 

* See Kant, Logik, Einleitung vii. Fries, Syst. der Logik, 
§. 41. Krug, Logik, §. 20. Thomson, Laws of Thought, p. 296. 

y Kant, Logik, Einleitung, vii. takes a different view. He 
regards the Principle of Contradiction as the criterion of the 
logical possibility of a judgment, that of Sufficient Eeason, as 
the criterion of its logical reality. But of judgments, as 
distinguished from the conclusions of syllogisms, the only 
logical reality is possibility. Directly I have ascertained two 
notions not to be contradictory to each other, I have made an 
actual judgment of the logical possibility of their coexistence : 
and to take any step beyond this, experience is required and 
not Logic. The difference between problematical and asser- 
torial judgments is extralogical, and depends on the question 
whether a logical judgment is or is not determined by expe- 
rience to be materially true. 



PROLEGOMENA LOGICA. 199 

Hypothetical and Disjunctive Judgments must 
be reserved for a separate examination. At present, 
we must proceed to investigate the laws of Rea- 
soning. This process differs from Judgment, as 
Judgment differs from Conception, in the nature 
of its preliminary data. In Judgment, concepts 
are given, thought being required to determine 
their possible coexistence in an object. In Rea- 
soning, one or more judgments are given, thought 
being required to determine what further judg- 
ments may be elicited from them. Under this 
head will thus be included not merely the ordinary 
Syllogism, but likewise (so far as they contain 
processes of thought at all) the immediate infer- 
ences of Opposition and Conversion. In all these, 
the material given prior to the act of thought is 
a judgment ; and the process of judging from 
concepts is thus not included, but presupposed ; 
the conclusion being always a different judgment, 
either in form, as regards Quantity, Quality, or 
Relation, which is the case in immediate conse- 
quences ; or partially in matter, which is the case 
in mediate reasoning by syllogism z . The common 

2 See Kant, Logik, §. 44. His theory of contraposition 
affecting the modality of the judgment is untenable, and 
seems to result merely from that excessive love of system 
which must bring in four forms somehow. The supposed 
demonstrative character of the conclusion in contraposition 
is merely a necessity of consequence from the position of the 
premise ; a character which is found in all logical reasoning 
whatever. 



200 PROLEGOMENA LOGICA. 

arrangement, therefore, which places immediate 
inference in the second part of Logic, is objection- 
able \ 

Opposition may be treated in two points of 
view. Firstly, as a relation between two given 
propositions : secondly, as a process of inference, 
in which, one proposition being given, another 
may be determined. In the former character, it 
is merely an explanation of the meaning of certain 
logical terms ; in the latter, it is a process of 
reasoning, a deduction of one proposition as con- 
clusion from another as premise, and governed, 
as we shall see, by the same laws as the mediate 
inference \ The primary processes, on which the 

* This order, however, has by no means been uniformly 
adopted by Logicians. Aristotle treats of Opposition in the 
De Interpret atione, and of Conversion in the Prior Analytics. 
Wolf separates Opposition and Conversion, considered as 
relations between two given propositions, from the processes 
of inference derivable from each. The former is treated in 
connection with Judgment; the latter, under the name of- 
Immediate Consequence, in connection with Eeasoning. 
Kant and his followers treat immediate consequences as 
reasonings, under the name of Syllogisms of the Understanding ; 
an arrangement which is logically correct, whatever may be 
the psychological objections to the nomenclature. 

b On account of this identity of law, various attempts have 
been made by ingenious writers to reduce immediate con- 
sequences to the mediate form. Thus Wolf exhibits sub- 
altern opposition as a syllogism with the minor premise, 
" Some Ais A;" thus perversely representing the law of thought,, 
which governs the reasoning process in general, as a part of 
the special matter given preliminary to a particular act. Still 



PROLEGOMENA LOGICA. 201 

rest may be made to depend, are those of Sub- 
altern and Contradictory Opposition; the former 
being grounded on the Principle of Identity, and 
the latter on those of Contradiction and Excluded 
Middle. Thus in the proposition, " All A is some 
B," an identity is stated between the whole of the 
objects thought under the concept A, and a portion 
of those thought under B c . The conclusion, 
" Therefore some A is some B," proceeds on the 
principle, that every part of A must be identical 
with a part of that which has been given as 

more absurd is the elaborate system which Krug, after a hint 
from Wolf, has constructed, in which all immediate infer- 
ences appear as hypothetical syllogisms; a major premise 
being supplied in the form, " If all A is B, some A is B." 
The author appears to have forgotten, that either this premise 
is an additional empirical truth, in which case the immediate 
reasoning is not a logical process at all; or it is a formal 
inference, presupposing the very reasoning to which it is 
prefixed, and thus begging the whole question. 

c Throughout the following pages, in order to exhibit the 
law of thought more clearly in each case, I have, in con- 
formity with the views of Sir William Hamilton, stated the 
quantity of the predicate as well as of the subject in each 
proposition. Of the value of this addition to the ordinary 
logical forms, I have elsewhere expressed my opinion. {North 
British Review, No. 29.) I have not, therefore, thought it 
necessary to enter into an elaborate examination of it here ; 
especially as it is sufficient for my purpose to bring forward 
only those forms of reasoning universally admitted by 
logicians. In quantifying the predicate in these instances, 
we only express what every treatise on Logic tells us to 
understand ; viz. that the predicate of an affirmative pro- 
position is not distributed ; i. e. is thought as particular. 



202 PROLEGOMENA LOGICA. 

identical with all A. This process resembles the 
inference in an affirmative syllogism ; except that 
in the latter there is given a double identity ; 
firstly, of the middle term with a part of the 
major ; and secondly, of the minor with a part 
of the middle. The inferences of Contradictory- 
Opposition are based on the Principles of Con- 
tradiction and Excluded Middle. By the former, 
when one of two contradictory judgments is given 
as true, we infer that the other is false ; and by 
the latter, when one is given as false, we infer 
that the other is true. The remaining inferences 
of Opposition may be reduced to combinations of 
the above. 

The several processes of Conversion, if the 
predicate is quantified as well as the subject, may 
be reduced to Simple Conversion only ; and even 
under the old system, Conversion per accidens may 
be regarded as a combination of Simple Conversion 
with one of the inferences of Opposition d . Simple 
Conversion is thus the only one which it is ne- 
cessary to examine. This cannot properly be 
regarded as a process of judgment ; for either 
the converted proposition is a new judgment 
distinct from the exposita, or it is merely the 

d Thus Aldrich analyses conversion per accidens. " Sit 
vera E : Ergo et ejus simpliciter conversa: Ergo et converse 
subalternata : qua? est expositse conversa per accidens. Sit 
vera A: Ergo et ejus subalternata: Ergo et subalternatse 
simpliciter conversa: quae est expositse per accidens." 



PROLEGOMENA LOGICA. 203 

same judgment expressed in different language. 
In the former case, it is an inference from a 
premise, and consequently a process of reasoning : 
in the latter, there is no process of thinking at all, 
but merely a change in the language by which a 
given thought is expressed. The former is the 
preferable view, so long as the subject and pre- 
dicate of a proposition are viewed in the relation 
of whole and part, whether by the inclusion of 
the subject under the extension of the predicate, 
or of the predicate in the comprehension of the 
subject. For the inversion of the relations of 
whole and part is sufficient to constitute a new 
judgment. But in the system of Sir W. Hamilton, 
in which every proposition is reduced to an 
equation, or rather to an identification of object 
between the two terms, the latter view seems 
more accurate ; it being manifestly the same thing 
to identify the object thought under A with that 
of B, and that thought under B with that of A. 

To opposition and conversion must be added a 
third process, that of the immediate consequence 
of one equipollent proposition from another 6 . 
The equipollence in some cases can only be deter- 
mined materially; and the consequence is then 

e See Wolf, Philosophia Rationalis, §. 445. Fries, System der 
Logik, §. 47. The former has not accurately distinguished 
the material from the formal cases of this consequence; 
and it was, probably, this confusion that led Kant to reject 
the inference altogether. 



204 PROLEGOMENA LOGICA. 

extralogical ; as in the instance cited by Wolf, 
Titius est pater Caii, ergo Cains est films Titii : 
but there are other instances in which the con- 
sequence is formal, and determined solely by the 
laws of thought. Thus, by the principle of contra- 
diction, from the premise, All A is B, follows the 
immediate inference, No A is not-B, in which is 
produced a change of quality from affirmative to 
negative. In this way, when one predicate is 
affirmed of a subject, its contradictory may always 
be denied. The process commonly called Con- 
version by Contraposition, is properly the simple 
conversion of this equipollent proposition g . 

The whole of the preceding observations clearly 
point out the view in which Logic and Psychology 
must coincide concerning the nature and principles 
of the Syllogism. The former, as the science of 
the laws of pure thinking, has nothing to do with 
the inferences of more or less probability furnished 
by the analogies of this or that branch of physical 
science, nor even with the general constitution of 
the material world, so far as it is known to us only 
empirically as a fact. Its only province is with 
those inferences which are necessitated by the laws 
of thought; which, certain data being furnished, we 
cannot but draw as consequences. That the pre- 
mises of a syllogism necessarily imply and contain 
the conclusion, is so far from being an imper- 
ii This has been remarked by Fries, §. 49. e. and recently 
by Mr. Karslake, Aids to the Study of Logic, p. 65. 



PROLEGOMENA LOGICA. 205 

fection in Logic, that it is a necessary conse- 
quence of the supposition that thought is go- 
verned by laws at all. And in accordance with this 
conclusion, Psychology teaches us that thought 
is representative and reflective, not presentative 
and intuitive ; that, having no positive operation 
beyond the field of possible experience, its laws 
can only be analytical, and its processes must lead 
not to the acquisition of new knowledge, but to 
the modification of the old. It only remains to 
exemplify this result, by applying it to the ordi- 
nary forms of the logical syllogism. 



Fig. 1. 




Fig. 2. 


All M is some P. 


No M is any P. 


No P is any M. 


All S is some M. 


All Sis some M. 


All S is some M 


All S is some P. 


.-. No S is any P. 


.-. No S is any P. 


Fig. 3. 




All M is some P. 


No JV 


[ is any P. 


All M is some S. 


All IV 


[ is some S. 


.*. Some S i 


s some P. 


.♦. Some 


S is not any P. 



The above examples will suffice as specimens 
of the different forms of affirmative and negative 
reasoning admitted by the three Aristotelian 
figures. The fourth figure might be easily sub- 
jected to the same treatment ; but it is preferable 
to regard its moods as inverted forms of the first. 
On inspection of these specimens, it appears, that 
the Principle of Identity is immediately applicable 
to affirmative moods in any figure, and the Prin- 



206 PROLEGOMENA LOGICA. 

ciple of Contradiction to negatives. In Barbara, 
for example, the minor term all S is identical with 
a part of M, and consequently with a part of that 
which is given as identical with all M, namely, 
some P. In Darapti, the minor term some S is 
identical with all M, and consequently with some 
P. The principle immediately applicable to both 
is the axiom, that what is given as identical with 
the whole or a part of any concept, must be 
identical with the whole or a part of that which 
is identical with the same concept. This may be 
briefly expressed by the Principle of Identity, 
Every A is A. In Celarent, Cesare, and Felapton, 
some or all S, being given as identical with all or 
some M, is distinct from every part of that which 
is distinct from all M \ This is briefly expressed 
by the Principle of Contradiction, No A is not-A. 

These two laws govern all the moods of Cate- 
gorical Syllogism, including under them as sub- 
ordinate rules the dictum de omni et nullo, or the 
nearly equivalent axiom, nota notce est nota rei 
ipsius; as well as the distinct axioms which have 
been framed by different logicians as rules of the 
second and third figures 1 . The process of Re- 

h Under the system of a quantified predicate, the second 
figure admits of affirmative syllogisms, which, like the rest, 
may be referred to the principle of Identity. 

1 As by Lambert, Neues Organon, part i. §. 232. Kant, Logik, 
§.71. Sir W. Hamilton in Mr. Thomson's Laws of Thought, 
p. 248. where they are given correctly as special applications 
of a more general principle. 



PROLEGOMENA LOGICA. 207 

duction, which is properly and necessarily adopted 
by those logicians who,, with Aristotle and Kant, 
acknowledge the principle of the first figure only, 
now becomes unnecessary and inconsistent ; inas- 
much as all the syllogistic figures are exhibited as 
equally direct exemplifications of the same general 
law. For the same reason, the distinction adopted 
by Kant between Syllogisms of the Understanding 
and Syllogisms of the Reason, in addition to the 
psychological impropriety of distinguishing two 
faculties of thought k , is now shewn to be logically 
untenable also ; the processes of immediate and 
mediate reasoning being exhibited as cognate acts 
of thought, governed by the same general laws, 
and differing only in their material data. 

By bearing in mind what has been above said of 
the nature of thought and its laws, we shall also 
be enabled to take a juster view of a process more 
or less misrepresented in the majority of logical 
treatises, Induction. Scarcely any logician has 
accurately distinguished between Formal Induction, 
in which the given premises necessitate the con- 
clusion in conformity with the laws of thought, 
and Material Induction, in which the conclusion 
may be inferred with more or less probability from 
additional data not furnished by the premises; — 
between what we must know as thinkers, and what 

k On this question, see Sir W. Hamilton, Edinburgh Review, 
No. 99. p. 205. Cousin, Leqons sur la PhilosopJiie de Kant, 
p. 168. Krug, Logik, §. T4. 



208 PROLEGOMENA LOGICA. 

we may know as investigators of nature. By some 
logicians, Induction is treated as a Syllogism in 
Barbara, with the major or minor premise suppressed ; 
the advocates of this view overlooking the fact, 
that the suppression of either premise leaves a 
deficiency to be supplied independently of the act 
of thought, and thus reduces the whole process 
from formal to material ; — to say nothing of the 
inversion of the reasoning as actually performed, 
and the destruction of all foundation for the 
syllogistic process from universals to particulars, 
by making every universal premise itself a deduction 
from a higher one. By others, Induction is repre- 
sented, according to the Baconian view, as an in- 
terrogation of nature, by the selection, in any 
physical investigation, of such phenomena as may 
indicate the existence of a general law. Here it is 
forgotten, that the fact that nature proceeds by 
uniform laws at all, is a truth altogether distinct 
from the laws of thought, and, if not of wholly 
empirical origin, at least one which cannot be 
ascertained a priori by the pure understanding. 
Others again, struck by the physical difficulty of 

1 Two distinguished exceptions must however be noticed. 
Aristotle's account of Induction, in Anal. Pr. ii. 23. incomplete 
as it is in many respects, has the merit of adhering accurately 
to the formal view of the process. And the admirable Article 
on Logic by Sir W. Hamilton, in No. 115. of the Edinburgh 
Keview, exhibits for the first time the logical character of 
Induction, divested of its material incumbrances and formal 
perversions. 



PROLEGOMENA LOGICA. 209 

an exhaustive enumeration of individual cases, 
endeavour to effect a compromise between material 
probability and formal necessity, by describing the 
instances cited as representatives or samples of their 
class; as if the nature of samples and representa- 
tives could be made known by an innate principle 
of the mind, independently of experience. Even 
the wonderful acuteness of Kant in all questions 
between matter and form appears to have deserted 
him here ; and, by describing Induction as a Syllo- 
gism of the judgment, furnishing a logical presump- 
tion of a general conclusion, he not only encumbers 
the science with an extralogical process, but neglects 
altogether the really formal reasoning which it is 
the duty of the logician to take into account. 

The truth is, that there are two totally distinct 
processes confounded under the general name of 
Induction. The Baconian or Material Induction 
proceeds on the assumption of general laws in the 
relations of physical phenomena, and endeavours, 
by select observations and experiments, to detect 
the law in any particular case. This, whatever be 
its value as a general method of physical investi- 
gation, has no place in Formal Logic. The Aris- 
totelian or Formal Induction proceeds on the 
assumption of general laws of thought, and inquires 
into the instances in which, by such laws, we are 
necessitated to reason from an accumulation of 
particular instances to an universal rule. The 
process in this case may be affirmative or negative ; 

p 



210 PROLEGOMENA LOGIC A. 

and it is governed, like other formal reasonings, by 
the general laws of Identity and Contradiction. 
Specimens of its several forms may be exhibited as 

follows : 

Affirmative Induction. 



X, Y, Z, are some B. 
X, Y, Z, are all A. 

.-. All A is some B. 



X, Y, Z, are some B. 
X, Y, Z, are some A. 
.*. Some A is some B. 



Negative Induction. 



X, Y, Z, are not any B. 
X, Y, Z, are all A. 
.*. No A is any B. 



X, Y, Z, are not any B. 
X, Y, Z, are some A. 
/. Some A is not any B. 



Other moods may be added to these, by varying 
the quantity of the predicate in the major premise. 
By assigning, in conformity with the system of Sir 
W. Hamilton, a definite quantity to the predicate 
in all affirmative propositions, we are enabled to 
avoid that ambiguity of the copula which has 
hitherto been the main defect in the logical analysis 
of inductive reasoning 111 . The relation of whole 
and part between the terms of the proposition 
being thus dispensed with, the subject is no longer 
represented as at one time contained under, at 
another constituting its predicate ; but each term, 
in every case, is equated, or identified as to its 
object, with the whole or a part of the other. 

Under this system, it is no longer necessary to 

distinguish Induction from the third figure of 

Syllogism, as this figure, with a definite predicate, 

will admit of universal as well as particular con- 

m See Sir W. Hamilton, Edinburgh Beview, No. 115, p. 228. 



PROLEGOMENA LOGIGA. 211 

elusions. Indeed, every Syllogism in this figure, 
in which the minor premise is collective, may be 
regarded as a logical Induction. In this point of 
view, it is manifestly governed by the same laws as 
the syllogism, the affirmative moods by the Prin- 
ciple of Identity, and the negative by the Principle 
of Contradiction. The so-called imperfect Induc- 
tion is altogether extralogical. The constituted 
whole can in thought be identified only with the 
sum total of its parts, not with a few represent- 
atives ; and without such identification no inference 
can be necessitated by the laws of thought. The 
physical difficulty of adducing all the members of a 
given class is a purely material consideration, like 
that of the truth of the premises in a syllogism, 
and is assumed, not investigated, by the logician. 
But without such a preliminary datum, we have 
no materials for drawing an universal conclusion 
by logical Induction. 

Thus far we have shewn the several forms of 
mediate categorical reasoning to depend on two 
necessary laws of thought, the Principles of Identity 
and Contradiction. A separate examination is 
needed to ascertain the character of the Hypothe- 
tical Propositions and Syllogisms, which, as I am 
inclined to think, has not hitherto been accurately 
exhibited, even by the best logicians of the formal 
school. 

By Kant and his followers, the Hypothetical 
Proposition is described as representing a form of 

p2 



212 PROLEGOMENA LOGICA. 

judgment essentially distinct from the categorical ; 
the latter being thoroughly assertorial, the former 
problematical in its constituent parts, assertorial 
only as regards the relation between them. Two 
judgments, each in itself false, may thus be hypo- 
thetically combined into a single truth; and this 
combination cannot be reduced into categorical 
form n . The Hypothetical Syllogism, in like manner, 
is a form of reasoning distinct from the categorical 
and not reducible to it, being based on a different 
law of thought, namely, the logical Principle of 
Sufficient Reason, a ratione ad rationatum, a nega- 
tions rationati ad negationem rationis valet con- 
seqnentia °. 

Of this principle, as applied to judgments, I have 
before remarked, that it is not a law of thought, 
but only a statement of the necessity of some law 
or others. As applied to syllogisms, it has the same 
character. It states the fact, that whenever a con- 
dition, whether material cause of a fact or formal 
reason of a conclusion, exists, the conditioned fact 
or conclusion exists also. Thus viewed, it is not 
the law of any distinct reasoning process, but a 
statement of the conditions in which laws of nature 
or of thought are operative. When a material 
cause exists, its material effect follows, and the 
phenomenon indicates a law of nature : when a 

n See Kant, Logik, §. 25. Krug, Logik, §. 57. Fries, 
der Logik, §. 32. 

Kant, §. 76. Krug, §. 82. Fries, §. 58. 



PROLEGOMENA LOGICA. 213 

logical premise is given, its logical conclusion fol- 
lows, and the result indicates a law of thought. 
What law, must in each case be determined by the 
particular features of the phenomenon or reasoning 
in question ; but a statement of this kind is dis- 
tinguished from laws of thought, properly so called, 
by the fact, that it cannot be expressed in a sym- 
bolical form : we require the introduction of a 
definite notion, Cause, Reason, Condition, or some- 
thing of the kind, which is a special object of 
thought, not the general representative of all 
objects whatever. The principle in question is 
thus only a statement of the peculiar character 
of certain matters about which we may think, and 
not a law of the form of thought in general. 

It is obvious that the relation of premises and con- 
clusion in a syllogism may, like any other relation of 
condition and conditioned, be expressed in the form 
of a hypothetical proposition : " If all A is B, and 
all C is A, then all C is B :" and the actual asser- 
tion of the truth of these premises will furnish at 
once a so-called hypothetical syllogism : " But all 
A is B, and all C is A, therefore all C is B." This 
was observed by Fries, who hence rightly maintains 
that analytical hypothetical judgments are formal 
syllogisms p . It is strange that, after this, he 
should not have gone a step further, and discovered 
that synthetical hypothetical judgments are asser- 
tions of material consequences. The judgment, ** If 

p System der Logik, §.44. 



214 PROLEGOMENA LOG1CA. 

A is B, C is D," asserts the existence of a conse- 
quence necessitated by laws other than those of 
thought, and consequently out of the province of 
Logic. The addition of a minor premise and con- 
clusion in the so-called hypothetical syllogism, is 
merely the assertion that this general material 
consequence is verified in a particular case. 

The distinction so much insisted on by the 
Kantians, of the problematical character of the two 
members of a hypothetical judgment, is, like the 
whole Kantian doctrine of modality, of no conse- 
quence in formal Logic. All formal thinking is, 
as regards the material character of its objects, 
problematical only. Formal Conception pronounces 
that certain objects of thought may possibly exist, 
leaving their actual existence to be determined by 
experience. Formal Judgment decides on the 
possible coexistence of certain concepts; and Formal 
Reasoning, on the truth of a conclusion, subject to 
the hypothesis of the truth of its premises. 

To state that this hypothesis is in a certain in- 
stance true, adds nothing to the logical part of the 
reasoning, but only verifies the empirical prelimi- 
naries which the logician in every case assumes as 
given. To exhibit a formal consequence hypo- 
thetically, is only a needless reassertion of the 
existence of data which the act of thought pre- 
supposes. To exhibit a material consequence 
hypothetically, is not to make it formal, but only 
to state that, in a certain given instance, a conse- 



PROLEGOMENA LOGICA. 215 

quence not cognisable by Logic takes place. The 
sequence of" C is D," from "A is B," is not one whit 
more logical than it was before ; it is only stated to 
take place materially in the present case. 

The omission of hypothetical syllogisms has 
frequently been blamed as a defect in Aristotle's 
Organon ; and his French translator takes some 
fruitless pains to strain his text,, in order to make 
out that he does in fact treat of them q . If there 
is any truth in the preceding observations, it will 
follow, that Aristotle understood the limits of Logic 
better than his critics ; and that his translator had 
better have allowed the omission as a merit than 
have attempted to deny it as a fault. When the 
hypothetical proposition states a formal conse- 
quence, the reasoning grounded upon it may always 
be reduced to categorical. When it states a ma- 
terial consequence, it states what the logician, as 
such, cannot take into account. Aristotle is there- 
fore quite right in saying, that in this case the 
conclusion is not proved, but conceded*. Syllogism 
may be employed as a logical proof of the ante- 
cedent : the consequent is admitted to follow on 
grounds which the logician, as such, does not 
investigate, but which may be warranted by the 
principles of this or that material science. 

The true character of hypothetical reasoning is 

i St. Hilaire, Logique d'Aristote Traduite en Frangais, Preface, 
p. lx. 

T Anal. Prior, i. 23. 11. 



216 PROLEGOMENA LOGICA. 

lost sight of in the examples commonly selected by 
logician s, which have for their subject a proper 
name, and indicate, not a general relation of reason 
and consequent between two notions, but certain 
accidental circumstances in the history of an indi- 
vidual. The adoption of this type has led to the 
logical anomaly, that the propositions of a hypo- 
thetical syllogism are generally stated without any 
designate quantity ; whereas it is obvious that, 
wherever concepts are compared together in any 
form of reasoning, two distinct conclusions may 
follow, according to the quantity assigned. For 
example, to the premise, " If men are wise, they 
will consult their permanent interests," we may 
supply two minors and conclusions, in the con- 
structive form, according as we affirm the ante- 
cedent of all men or of some. It thus becomes 
necessary to distinguish between two different 
kinds of apparent hypothetical syllogisms, those in 
which the inference is from a general hypothesis to 
all or some of its special instances, and those in 
which a relation between two individual facts is 
assumed as an hypothesis leading to a singular 
conclusion. The former contain a general relation 
of determining and determined notion, which may 
always be expressed in three terms ; the occasional 
employment of four being only an accidental variety 
of language. Thus the general assertion, " If any 
country is justly governed, the people are happy," 
is equivalent to, " If any country is justly governed* 



PROLEGOMENA LOGICA. 217 

it has happy people." This we may apply to 
special instances ; all countries, some countries, or 
this country, being asserted to be justly governed : 
and this is properly hypothetical reasoning. The 
latter denote only a material connection between 
two single facts, either of which may, to certain 
minds possessed of certain additional knowledge, 
be an indication of the other ; but the true ground 
of the inference is contained in this additional 
knowledge, and not in the mere hypothetical 
coupling of the facts by a conjunction. This is 
not hypothetical reasoning ; i. e. it is not reason- 
ing from the hypothesis, but from other circum- 
stances not mentioned in the hypothesis at all 3 . 

8 This may be made clearer by an example. The following 
is cited by Fries, as an instance of a hypothetical proposition, 
not reducible to categorical form. " If Cams is free from 
business, he is writing poetry." This may be interpreted to 
mean either, generally, " whenever Caius is disengaged, he 
writes poetry ;" or, specially, " if he is now disengaged, he is 
now writing poetry." Under the former interpretation, it is 
a general hypothesis, which may be applied as a major 
premise to particular instances : but in this case the true 
form of the reasoning is, " All times when Caius is disengaged, 
are times when he writes poetry ; and the present is such a 
time." Under the latter interpretation, it is one of the cases of 
a material connection of two facts mentioned in the text. Now 
in this last case, it is obvious that the inference is really 
made, not from the hypothesis, but from some circumstance 
known to the reasoner, but not appearing in the proposition. 
Any man being asked, " Why do you infer that Caius, being 
now disengaged, is writing poetry?" would reply, " Because 
he told me he should do so;" or something of the kind. 
Assuredly he would never dream of replying, " Because if he 



218 PROLEGOMENA LOGICA. 

It thus appears, that the only hypothetical judg- 
ment which can be employed as the real major 
premise of a syllogism, may be expressed in the 
form, " If any A is B, it is C," where A, B, and C 
represent concepts or general notions. The com- 
plete categorical equivalent to this is, " Every A 
which is B is C, because it is B," which admits of 
two interpretations, according as B stands for the 
physical cause of the fact, or for the logical reason 
of our knowing it. In the latter case, the judgment 
is analytical, and represents a disguised formal con- 
sequence with B as a middle term : e. g. " Every 
man who is learned has studied, because he is 
learned." Here the notion of study is implied in 
that of learning, and the major premise is, " All 
learned beings have studied." The hypothetical 
proposition thus becomes a complete syllogism, to 
which the subsequent consequence is related as an 
episyllogism*. In the former case, where B stands 

is now disengaged he is writing." In this case then he does 
not reason from the hypothesis, and the expressed propositions 
do not compose a syllogism. 
* Thus : 

Hypothetical Syllogism. Categorical Analysis. 

If any man is learned, he All learned beings have 

has studied : studied : 

Some men are learned ; All learned men are learned 



Some men have studied. 



beings ; 
All learned men have 

studied : 
Some men are learned men ; 
Some men have studied. 



PROLEGOMENA LOGICA. 219 

for a physical cause, the judgment is synthetical, 
and indicates a material consequence, which it 
requires some additional knowledge of facts to 
reduce to formal : e. g. " All wax exposed to the 
fire melts, because it is exposed." Here, on 
material grounds, we know that we cannot supply 
the premise, "All bodies exposed to the fire melt;" 
but only, "All bodies soluble by heat and exposed 
to the fire melt." In this case the consequence is 
extralogical, and requires additional data not given 
in the thought. But here also, when the judg- 
ment in question is employed as the premise of a 
reasoning, the conclusion follows categorically ; 
though the premise itself cannot, as it stands, be 
proved by a prosy llogism u . 

The Disjunctive Judgment is usually described 
as representing a whole divided into two or more 
parts mutually exclusive of each other ; and the 
Disjunctive Syllogism is supposed to proceed either 
from the affirmation of one member to the denial 
of the rest, or from the denial of all but one to 

u The analysis in this case may be exhibited thus : 



Hypothetical Syllogism. 
If any wax is exposed to the 

fire it melts : 
This wax is exposed to the 

fire; 
.-. This wax melts. 



Categorical Equivalent. 
All wax exposed to the fire 

melts (because exposed) : 
This wax is exposed to the 

fire; 
This wax melts. 



The parenthesis indicates the material ground of the major 
premise. 



220 PROLEGOMENA LOGICA. 

the affirmation of that one, by the Principle of 
Excluded Middle x . 

This can scarcely be regarded as a correct 
analysis of the process, unless the two members 
are formally stated as contradictory. The Prin- 
ciple of Excluded Middle asserts that every thing 
is either A or not A, that of two contradictories, 
one must exist in every object; as the Principle of 
Contradiction asserts that they cannot both exist. 
But if the two members are not stated as contra- 
dictories, if my disjunctive premise is, " All C is 
either A or B," I make the material assertion that 
All C which is not A is B. If then I reason, 
" This C is not A y , therefore it is B," I employ 
the Principle of Identity in addition to that of 
Excluded Middle. Again, if I maintain that No 
C can be both A and B, I make the material 
assertion that No C which is A is B ; and from 
hence to reason, " This C is A, therefore it is 
not B," requires not the Principle of Excluded 
Middle, but that of Contradiction. In the first 
case, the Excluded Middle does not lead directly 
to the conclusion, but only to the contraposition 
of the minor premise. When we deny this C to 
be A, this principle enables us to assert that it is 
not-A, and hence to bring the reasoning under 

* Kant, §. 27 sqq, 77, 78. Krug, §. 57, 84, 85. Fries, 
§. 33, 59. 

y The indefinite minor, " but it is not A," is as objection- 
able in this syllogism as in the conditional. 



PROLEGOMENA LOGICA. 221 

the Principle of Identity. But in the second case, 
in which one of the opposed members is affirmed, 
the ground on which we deny the other, is not 
because both cannot be false, but because both 
cannot be true. 

It may be questioned whether this second in- 
ference is warranted by the form of the disjunctive 
premise. Boethius calls it a material consequence* ; 
and, in spite of the many eminent authorities on 
the other side, I am still disposed to think he is 
right. But let us grant for a moment the opposite 
view, and allow that the proposition, " All C is 
either A or B," implies, as a condition of its truth, 
" No C can be both a ." Thus viewed, it is in reality 
a complex proposition, containing two distinct 
assertions, each of which may be the ground of 
two distinct processes of reasoning, governed by 
two opposite laws. Surely it is essential to all 
clear thinking, that the two should be separated 
from each other, and not confounded under one 
form by assuming the Law of Excluded Middle to 
be, what it is not, a complex of those of Identity 
and Contradiction. Thus distinguished, the moods 
of the disjunctive syllogism are mere verbal vari- 



z De Syll. Hyp. lib. i. Opera, p. 616. Cf. Galen. Isagoge 
Dial. p. 11. 

* Aquinas, Opusc. xlviii. De Enunciations, c. xiv. Krug, 
Logih, §.86. 



222 



PROLEGOMENA LOGICA. 



ations from the categorical form, and may easily 
be brought under its laws b . 

The preceding discussion may appear to some 
readers of trifling importance ; and some apology 
for its length may be thought necessary. I believe 
nothing to be unimportant in a logical work, which 
tends to mark out more accurately the nature of 
thought and its laws, to exhibit more precisely the 
formal character of logical processes, and to clear 
the subject from the remaining excrescences and 
inconsistencies, with which, even in the writings 
of the best modern Logicians, it is still occasionally 
encumbered . Either Logic is not worth studying 



b Thus: 

Modus tollendo ponens. 
Every C which is not A is B 
Every! 
Some Y 
This J 
It is B. 



C is a C which is 
not A. 



Modus ponendo tollens. 

No C which is A is B. 
Everyl 

Some f C is a C which is A. 
This J 
.-. It is not B. 

The first is governed by the Principle of Identity, and the 
second by the Principle of Contradiction. 

c For example: Fries, after expressly distinguishing the 
Principle of Sufficient Eeason from the other Formulae of 
Thought, as not being a principle of philosophical or formal 
Logic, places it in his next chapter in a coordinate position 
with them, as the distinctive law of hypothetical syllogisms. 
Krug describes it in one place as the highest principle of 
syllogism in general, and in another as the special principle 
of a single class of reasonings. It is proper to speak with 
respect even of the errors of the great philosopher of 



PROLEGOMENA LOGICA. 223 

at all, or it is worth studying in the utmost com- 
pleteness and exactitude of which it is susceptible. 
The length to which these remarks have run is 
justified, indeed demanded, by the eminent authors 
from whom the writer has ventured to dissent ; — 
authorities, whose mere assertions in matters of 
logical science are not to be lightly regarded nor 
hastily departed from. Even if the views here 
advanced should be found on examination to be 
less tenable than the author believes them to be, 
they will not have been without their use, if, by 
calling the attention of others to one or two of 
the weaker defences of the received doctrines of 
Formal Logic, they should indirectly lead to a 
more satisfactory vindication of the positions as- 
sailed. 

It only remains to sum up as briefly as possible 
the results of the present chapter. Formal or 
Logical Necessity is dependent on one negative 
condition, and on three positive laws. The 
negative condition, or sine qua non of thought in 
general, is contained in the Principle of Sufficient 
Reason, which, however, in this relation, belongs 
to Psychology and not to Logic ; being only a 



Konigsberg ; but perhaps even Kant was in some degree 
biassed in his examination of logical processes, by an almost 
pedantic love of reproducing in every relation his four 
Functions of Judgment, and by the strange metaphysical 
theory which deduced the three Ideas of Pure Keason from 
the three kinds of dialectical syllogism. 



224 



PROLEGOMENA LOGICA. 



general statement of the conditions under which, 
in the existing constitution of man's mind, thought 
is possible; — its dependence, that is to say, on a 
higher thought, or on a fact of intuition. The 
three positive laws or fundamental principles 
assumed by Logic, as regulating all its actual 
processes, are those of identity, of Contradiction, 
and of Excluded Middle ; the last, however, 
operating in most cases in subordination to the 
other two. These three are the highest and 
simplest forms of identical judgments, to one of 
which all analytical thinking may ultimately be 
referred : and all pure thinking may be shewn, on 
psychological grounds, to be of a strictly analytical 
character. The necessity arising from these laws 
is that of the harmony of thought with itself, — of 
its conformity to its own ruling principles ; as the 
forms of necessity noticed in the previous chapters 
were those arising from the relation of thought to 
the laws and conditions of intuition,— the requisite 
harmony of the several mental faculties one with 
another. These two harmonies constitute respec- 
tively Formal and Material Truth. Truth, relatively 
to man, cannot be defined as consisting in the con- 
formity of knowledge with its object ; for to man 
the object itself exists only as it is known by one 
faculty or another. Material Truth consists rather 
in the conformity of the object as represented in 
thought with the object as presented in intuition : 
and of this no general law or criterion can be 






PROLEGOMENA LOGICA. 225 

given ; its essence consisting in its adapting itself 
in every case to the diversities of this or that 
special presentation. But Logical Truth, which 
consists in the conformity of thought to its own 
laws, can be submitted to those laws as general 
and sufficient criteria ; criteria, however, not of 
the real and existent, but of the thinkable and 
possible. Of actual truth it furnishes one element 
only, which becomes truth or not in combination, 
according as, upon further examination, it is found 
to be in conformity or at variance with the co- 
ordinate decisions of experience. By the same 
criteria, we shall also be able to determine the 
logical or extralogical character of any portion of 
the contents of existing treatises on the science; 
according as it is a deduction of pure thinking 
from given materials, or a mixed process, com- 
bining the act of thought with the acquisition of 
further empirical data. On the distinction esta- 
blished between material and formal thinking, 
some further observations will be made in the next 
chapter. 



CHAP. VII. 

ON THE MATTER AND FORM OF THOUGHT, 

The distinction adopted between Matter and 
Form in common language, relatively to works of 
Art, will serve to illustrate the character of the 
corresponding distinction in Thought. The term 
Matter is usually applied to whatever is given to 
the artist, and consequently, as given, does not 
come within the province of the art itself to supply. 
The Form is that which is given in and through 
the proper operation of the art. In Sculpture, for 
example, the Matter is the marble in its rough 
state as given to the sculptor; the Form is that 
which the sculptor in the exercise of his art com- 
municates to it\ The distinction between Matter 
and Form in any mental operation is analogous to 
this. The former includes all that is given to, the 
latter all that is given by, the operation. In the 
division of notions, for example, whether performed 
by an act of pure thinking or not, the generic 
notion is that given to be divided ; the addition of 

a See Fries, System der Logik, §. 19. His division cor- 
responds to the above, though based on a somewhat different 
principle. 



PROLEGOMENA LOGICA. 227 

the difference in the act of division constitutes the 
species. And accordingly, Genus is frequently 
designated by logicians the material, Difference, the 
formal part of the Species. So likewise in any 
operation of pure thinking, the Matter will include all 
that is given to and out of the thought ; the Form 
is what is conveyed in and by the thinking act itself., 
The same analogy may be carried on in relation 
to what are called material and formal processes 
of thinking. It may happen on certain occasions 
that the marble given to the sculptor is insufficient 
for the completion of the statue. It becomes 
necessary, therefore, to suspend the artistic pro- 
cess itself, in order to obtain additional material ; 
and this provision of new material the artist does 
not undertake purely as a sculptor. So in relation 
to any process of thinking. The empirical data 
requisite for an act of conception, judgment, or 
reasoning, may be insufficient, and require the 
addition of fresh material not furnished by the 
mere act of thinking. The operation in this case 
is one of mixed or material thinking; i. e. of thinking 
preceded by an appeal to experience for the pro- 
vision of further data; and this appeal is no part 
of the duty of the logician, as such. Whereas, if 
the materials originally given are alone sufficient to 
necessitate, in obedience to the laws of thought, 
an act of conception, judgment, or reasoning, the 
process is properly distinguished as one of pure or 
formal thinking. 

q2 



228 PROLEGOMENA LOGICA. 

Notwithstanding this analogy, it is in many 
respects important that the matter and form of 
a thought should not be confounded with material 
and formal thinking respectively. Thinking is not 
always formal because its product has form, nor 
does the presence of a form in the antecedent of 
thought always necessitate a formal process in 
consequence. The sculptor, to continue our image, 
may ultimately complete his work with all the 
form and finish of art : it does not therefore follow, 
that all his material must have been given to him 
at once in the first instance. Or he may have 
carved with exactness one subordinate figure of 
a group : it does not therefore follow, that his 
material is sufficient to enable him to complete 
the whole. The present chapter is intended to 
point out more clearly the distinction and re- 
lation between the form of thought and formal 
thinking. 

The antithesis of matter and form, — the objective 
and the subjective, — the variable and the permanent, 
— the contingent and the necessary, runs through 
all the phenomena of consciousness. The mani- 
fold elements presented by any object of conscious- 
ness constitute the matter : the relations which 
the mind, acting by its own laws, institutes between 
the several elements as it combines them into an 
object, constitute the form b . In this point of 
view, Space and Time are called by Kant the 
b See Kant, Kritik der r. V. p. 32. (ed. Rosenkranz.) 



PROLEGOMENA LOGICA. 229 

Forms of the Sensibility in general, external or 
internal ; the objects of the former being neces- 
sarily regarded by the mind as lying out of our- 
selves in Space, the objects of the latter, as suc- 
ceeding one another in Time. These may thus 
be regarded as the subjective conditions under 
which sensibility in general is possible. The same 
antithesis may be carried through those special 
acts of consciousness, in which the understanding 
operates, whether in conjunction with the pre- 
sentative faculties, as in an act of mixed thinking ; 
or representatively, as in pure thinking. A savage, 
to adopt an illustration of Kant's c , sees a house in 
the distance, not knowing what it is. It is thus 
present to him only as an intuition in space. 
But the very same complex phenomenon is pre- 
sented to a man who knows it to be a building 
designed for the habitation of men. To the same 
sensible data, the understanding now adds its own 
contribution, by which the several presentations 
of sense are combined into one whole, under the 
general notion of a house. The sensible attributes 
here constitute the matter ; their union in a concept 
is the form. 

In Thought, as in Intuition, there is thus a 
variable and a permanent, an objective and a sub- 
jective element, a matter given to the thinker, 
a form communicated by the thinking act. In 
respect of the matter, concepts differ one from 
c Logik, Einleitung v. 



230 PROLEGOMENA LOGICA. 

another, as being composed of this or that variety 
of given attributes. In respect of the form, all agree, 
as being a collection of attributes representing an 
object. To every concept, it is essential that it 
possess in some degree distinctness and clearness; 
that we should be conscious, that is, of a plurality 
of attributes discerned from each other, and of 
their union in a definite whole. Distinctness and 
Clearness are thus the two Forms, constituting the 
Concept as such : the given attributes are the 
Matter, distinguishing it as a concept of this object 
or of that. The former is determined, as we have 
seen in the last chapter, in accordance with the 
general laws of Contradiction and Identity : the 
other is contained in each case in the special data 
preliminary to the act of thought. 

The matter and form of Judgments may be 
distinguished in the same manner as those of 
Concepts. The act of judging consists in regard- 
ing two given concepts as coexisting or not in 
one or more possible objects of intuition. The 
matter is thus given beforehand in the special 
concepts compared ; and by this, one judgment is 
distinguished from another, as a judgment about 
this or that thing. The elements essential to all 
judgments as such, are, firstly, that one or more 
objects be compared under each concept ; and, 
secondly, that those objects be pronounced iden- 
tical or distinct. We have thus the two Forms 
of Quantity and Quality ; the former being either 



PROLEGOMENA LOGICA. 231 

definite, as in the universal and singular judg- 
ments ; or indefinite, as in the particular d . 

To these two Forms of Judgment, two others 
are added by Kant, Relation and Modality. The 
former of these includes the three subdivisions of 
Categorical, Hypothetical, and Disjunctive, and is 
necessarily included among the forms of thought 
by those who adopt Kant's theory of the nature 
of these three kinds of propositions. But the view 
which has been taken of these in the last chapter 
precludes the admission of Relation as a distinct 
form from Quantity and Quality. Disjunctive 
judgments have there been treated as reducible 
to Categorical forms; and Hypotheticals, as con- 
taining, not a judgment, properly speaking, but 
a consequence, formal or material. In this case, 
the relation is not between the different parts of 
a single judgment, but between two judgments, 
one dependent on the other. The judgment 
proper being thus confined to the categorical 
form only, Relation becomes only a general ex- 

d The particular proposition is the true indefinite; the 
subject being taken indeterminately, in some part of its 
extension; while in the universal and singular propositions 
it is taken determinately, in its greatest or least extension. 
The proposition with no expressed quantity ought, as Sir W. 
Hamilton has observed, to be called indesignate. The form 
of quantity ought also, as in Sir W. Hamilton's system, to be 
expressed in both terms of the proposition. In the present 
work, however, I have selected my instances from the ordinary 
logical affirmatives with particular predicates. 



232 PROLEGOMENA LOGICA. 

pression for the connection of subject and pre- 
dicate under certain conditions of quantity and 
quality, and thus is not a special form of judg- 
ment, but a term equivalent to Form in general. 

As regards Modality, judgments, according to 
Kant, are of three kinds, problematical, assertorial, 
and apodeictical. The first are accompanied by 
a consciousness of the bare possibility of the 
judgment ; the second, by a consciousness of 
its reality ; the third, by a consciousness of its 
necessity. Modality is thus dependent on the 
manner in which a certain relation between two 
concepts is maintained, and may vary according to 
the state of different minds, the given concepts, 
and consequently the matter of the judgment, 
remaining unaltered 6 . These grounds are fully 
sufficient to establish modality, in the extent to 
which it is acknowledged by Kant and by Aris- 
totle*, as, in a psychological point of view, belong- 

e Kant, Logik, §.30. 

f Aristotle, in the De Interpretations, ch. 12. enumerates 
four modes of judgment, the necessary, the impossible, the 
contingent, and the possible. The addition of the true and 
the false is, I think, founded on a misinterpretation. These 
modes he reduces, in the Prior Analytics, i. 2. to the necessary 
and the contingent (tov e£ dvdyKrjs vndpxzw and tov ivbex^crBai 
virapxew). These, with the addition of the pure judgment 
{tov vnapxew), correspond to the division of Kant. The 
spurious modes admitted in abundance by the scholastic 
logicians are not forms of the judgment, but modifications 
of one of its terms only. They affect, that is, the subject 
alone, or the predicate alone, not the relation between the two. 



PROLEGOMENA LOGICA. 233 

ing to the form, not to the matter, of judgment. 
It is conveyed in the act of judging, not given in 
the preliminary materials, and affects the copula, 
not the predicate. But the forms cognisable by 
Psychology must not be confounded with the 
forms cognisable by Logic. The latter science is 
not concerned, as is sometimes maintained, with 
the Forms of Thought in general, but only with 
the forms of thought as related to pure or formal 
thinking. The meaning of this limitation will 
appear more clearly in the sequel. In this point 
of view, Modality stands on a very different footing 
from Quantity and Quality. In cases where a 
modal conclusion is drawn from modal premises, 
it is only the form of the conclusion as a judgment 
that differs from that of the pure syllogism : its 
relation to the premises as a conclusion from 
them, consequently the entire form of the reason- 
ing, is the same in both. Whereas, by the substi- 
tution of a negative premise for an affirmative, or 
of a particular for an universal, the conclusiveness 
of the premises as necessitating a consequence, 
and hence the whole form of the reasoning, will, 
in most cases, vanish altogether. For this reason, 
Modality, though psychologically a form of judg- 
ment, is not one of those forms that properly fall 
within the province of Logic. This will be made 
clearer when we come to treat of the matter and 
form of syllogisms g . 

s On the disputed question of the relation of Modals to 



234 PROLEGOMENA LOGICA. 

It thus appears, that the strictly logical Forms 
of Judgment may be reduced to two, Quantity and 
Quality. These are not, properly speaking, the 
result of Laws of Thought, except in those cases 
in which the judgment is an act of pure thinking ; 
viz. in analytical judgments, the forms of which, 
when affirmative, are determined by the principle 
of Identity, and when negative, by that of Contra- 
diction. In synthetical judgments, neither quantity 
nor quality can be determined by the laws of pure 
thinking; it being indifferently allowed to the 
logician, as such, to think all or some A may or 
may not be B. In these cases the judgment 
is determined by an act of mixed thinking, or 
thought cooperating with this or that special ex- 
perience. Nevertheless, here, as elsewhere, the 
forms of the judgment are added by, not given to, 
the thinker. In forming, for example, the judg- 
ment that gold is heavy, the experience of sight 
presents us with a round yellow body ; the ex- 
perience of pressure on the hand attests its weight. 
To unite these attributes, as belonging to one and 
the same subject, is an act, not of sensation, but of 
thought. The same is the case as regards quantity. 
I see a number of balls lying on a table, and pro- 
nounce at once that they are all white : I see 
another collection, and assert in like manner that 
some are white and some black. Here the senses 

Logic, some further remarks will be found in the Appendix, 
note G. 



PROLEGOMENA LOGICA. 235 

present only individual objects. This, this, and 
this, are within their province ; they know nothing 
of all or some. It is by an act of thought that the 
several individuals are regarded as constituting a 
whole, and a judgment pronounced concerning that 
whole or a portion of it. The psychological con- 
ditions of these acts of mixed thinking will be 
noticed hereafter. 

As conception furnishes the material for an act of 
judgment, so judgment furnishes the material for 
an act of reasoning. The Matter of the inference 
consists in the several propositions of which it is 
composed, and which vary in every different in- 
stance : its Form appears in the manner in which 
those propositions are invariably thought as con- 
nected together, as premises and conclusion : hence 
in the recognition of a relation of identity or con- 
tradiction between the terms as given in the ante- 
cedent and those connected by the act of reason- 
ing in the consequent. In immediate reasoning, this 
relation is direct ; and the form accordingly consists 
in the terms of the conclusion being in themselves 
identical or contradictory to those of the premise. 
In mediate reasoning, the relation is indirect ; and 
the act of reasoning consists, firstly, in the recogni- 
tion of the relation of each extreme to a middle 
term, and, secondly, in the inference of a cor- 
responding relation between the extremes them- 
selves. The Form of the Syllogism thus appears, 
firstly, in the repetition of the same term in each 



236 PROLEGOMENA LOGICA. 

premise ; and, secondly, in the quantity and quality 
of the conclusion, and in the sign of inference 
which indicates them as determined by the pre- 
mises \ 

In pure or logical reasonings, as in analytical 
judgments, the form of the conclusion is determined 
by the laws of Identity and Contradiction. But 
inferences, as well as judgments, are in some cases 
the result of an act of mixed thinking ; of reasoning, 
that is, in conjunction with an appeal to experience. 
This is sometimes distinguished by logicians as 
material consequence; the strictly logical operation 
being designated formal. In the earlier portion of 
the present chapter, it has been necessary to avoid 
this nomenclature; the object having been to shew 
that in every act of thought, pure or mixed, the 
product exhibits the distinct features of a matter 
given to, and a form given by, the thinker. The 
matter and form of thought are thus by no means 
coextensive with material and formal thinking; 
and it becomes therefore necessary to examine 
separately the propriety of these last expressions, 
and to determine what is the exact sense in which 
Logic is defined to be a Formal Science. 

h According to Kant, the premises are the matter of the 
syllogism, the conclusion the form. This view is with reason 
objected to by Krug, Logik, §. 72. The matter appears 
through the terms, in the conclusion as well as in the 
premises ; the form, as indicated by the relation in which 
the terms are thought to each other, appears in the premises 
as well as in the conclusion. 



PROLEGOMENA LOGICA. 237 

The distinction between formal and material, or, 
as for the present it is better to term them, between 
pure and mixed thinking, has not in general been 
consistently followed out by logicians. They have 
allowed the existence of material consequences, in 
which the conclusion does not follow from the 
given premises, but requires additional data from 
experience ; and these they have rightly regarded 
as extralogical ; but they have not observed that 
the same distinction is applicable to Apprehension 
and Judgment, as well as to Reasoning ; that there 
are pure and mixed concepts and judgments, as 
well as pure and mixed reasonings ; and that in 
every case the province of Logic is with the first 
only. In consequence of this, the province of 
Logic has been by some too much widened, and 
by others too much narrowed. On the one side, 
we are told that it can remedy indistinctness of 
apprehension and falsity of judgment ; — a pretension 
which, announced without limitation, is perfectly 
absurd : and on the other side, it has been described 
as concerned with the operation of reasoning only; 
apprehension and judgment being considered only 
in subordination to this. Neither view has been 
consistently carried out. The advocates of the 
former ought to have included within the province 
of Logic, Induction, Analogy, and the whole field 
of probable reasoning ; while the advocates of the 
latter ought to have taken notice of those forms of 



238 PROLEGOMENA LOGICA. 

pure thinking which are governed by the same 
laws as the formal syllogism. 

It would be more correct to distinguish, with 
regard to all the three operations of the under- 
standing, between those errors which arise from a 
defect in the thought itself, and those which arise 
from a defect in the corresponding experience. 
For example, my conception of a particular flower 
is obscure, when I have not noticed it so closely as 
to be able to distinguish it as a whole from certain 
others : it is Indistinct, when I know it as a whole, 
but have not analysed it so minutely, as to be 
able to enumerate its botanical characteristics. In 
these cases, the defect is empirical, and can only 
be remedied by closer attention to the individual 
flowers of that kind. But, on the other hand, my 
conception may be obscure, as containing attributes 
inconsistent with the existence of its object as an 
individual whole ; or it may be indistinct, as con- 
taining attributes incapable of coexisting with each 
other as parts of a whole. Thus we may be told 
to conceive a flower of no colour at all, or a flower 
which shall be both red and white on the same 
part of the same leaf. In these cases, the defect is 
in the thought itself. And accordingly, Logic is 
competent to declare the supposed object incon- 
ceivable. Again, a judgment may be empirically 
false, as asserting a combination of attributes never 
actually found in experience ; as if it is asserted that 






PROLEGOMENA LOGICA. 239 

a horse has five legs. It may be logically false, as 
coupling together attributes which contradict each 
other ; as if it is asserted that a quadruped has five 
legs. In the former case, I can contradict the 
assertion only by an appeal to the experience of 
all who are acquainted with the animal : in the 
latter, I can contradict it on logical grounds, as 
false in the thought itself. An inference, in like 
manner, may be empirically inconsequent, as 
grounded on a relation of phenomena not in- 
variable in nature : it may be logically incon- 
sequent, as deduced from premises not neces- 
sitating it by the laws of thought. Thus, if I am 
asked whether this particular fall of the barometer 
is a ground for asserting that it will rain within 
twelve hours, I can only reply, as a logician, that 
it is so, if all falls of the barometer are so : but 
whether this is the case in fact, cannot be decided 
by logic, but by experience. On the other hand, 
if it be expressly stated that some falls only of the 
barometer are indications of rain within twelve 
hours, I can at once decide that it is logically 
inconsequent to reason from a merely partial rule 
to any single instance : the rain may in this case 
be expected with more or less probability, but it 
cannot be inferred as a certainty. 

It thus appears, that in all the three operations 
of the understanding, Logic is equally competent 
to detect their internal vices, as thoughts trans- 
gressing their own laws ; and that in all it is equally 



240 PROLEGOMENA LOGICA. 

incompetent to detect their external vices, as 
thoughts inconsistent with experience. It can 
detect the inconceivability of a notion, the self- 
contradiction of a judgment, the inconsequence 
of a conclusion as not necessitated by given 
premises. It cannot supply the empirical defi- 
ciencies of a notion, nor determine the real exist- 
ence of its object : it cannot ascertain the truth or 
falsehood of a judgment as a statement of a fact : 
it cannot decide as to the necessary sequence of a 
conclusion from understood premises, or the pro- 
bability of its truth where the given premises are 
insufficient to necessitate it by the laws of thought. 
It remains to ascertain the exact meaning of the 
expressions formal and material thinking, as ap- 
plied respectively to those operations which do or 
do not fall within the province of Logic. 

Law and Form, though correlative terms, must 
not, in strict accuracy, be used as synonymous. 
The former is used properly with reference to an 
operation; the latter, with reference to its product. 
Conceiving, Judging, Reasoning, are subject to 
certain laws : Concepts, Judgments, Syllogisms, 
exhibit certain forms. But the laws of thought 
are not always competent to determine its form ; 
as has been already shewn in the case of all the 
products of mixed thinking. In a synthetical 
judgment, for example, the laws of thought can 
determine only its possible truth, which equally 
implies its possible falsehood ; thus leaving it 



PROLEGOMENA LOGICA. 241 

altogether undecided, whether the form of the 
judgment should be affirmative or negative, uni- 
versal or particular. The form in all these cases 
is determined by that universal tendency of the 
human mind, which has been noticed in a former 
chapter, the tendency to regard physical phe- 
nomena as indicating the existence of a substance 
or a cause similar to that of which we are directly 
conscious in our own mental states and operations. 
It is thus that, when experience presents certain 
phenomena in juxtaposition, the mind is invariably 
led to regard them as attributes of one and the 
same substance ; and this constitutes the form of 
all mixed concepts and judgments. And in like 
manner, when one phenomenon is the invariable 
consequent of another, the mind is irresistibly led 
to regard them as respectively cause and effect; 
and this constitutes the form in all cases of mixed 
inference. The same tendencies which thus co- 
operate with the presentations of experience in 
the acts of mixed thinking, cooperate in like 
manner with the laws of thought in acts of pure 
thinking. In the former case, the attributes are 
given as empirically related as intuitions ; in the 
latter, they are given as logically related as 
thoughts ; and in both they are regarded as 
mutually related to some unknown substance or 
cause. But that these tendencies, however uni- 
versal or irresistible, cannot properly be regarded 
as laws of thought or of intuition, is manifest from 

R 



242 PROLEGOMENA LOGICA. 

the fact, that they furnish no criterion for de- 
termining the legitimacy or illegitimacy of any 
product. Thoughts, whether empirically true or 
false, whether logically sound or unsound, in this 
respect present precisely the same features. An 
assertion, false in point of fact, or self-contradictory 
in point of thought, contains, as regards the sup- 
posed relation of attributes to a common substance, 
precisely the same form as one logically and em- 
pirically valid. The Principles of Substance and 
Causality are thus rather negative conditions than 
positive laws of thought. They have a psycho- 
logical relation to thought as it actually exists, 
explaining and accounting for the fact of its 
invariably assuming a certain form : but they have 
no logical relation to thought as it ought to be, 
and furnish no criterion of its validity in any 
special instance. 

Logical or pure thinking is not, therefore, called 
formal, because its product exhibits a form ; for 
the coexistence of matter and form is common 
to all thought, and to all spurious imitations of 
thought. But the justification of the terms formal 
and material, as applied to pure and mixed pro- 
cesses of thinking, is to be found in the circum- 
stance, that in the former, the act of thought is 
based on the form only of the preliminary data, 
without reference to the particular matter ; while, 
on the other hand, matter is necessarily taken into 
account in every process of mixed thinking. To 



PROLEGOMENA LOGICA. 243 

an act of logical conception, for example, it is 
not necessary to examine in any case the special 
character of the attributes, as having been actually 
combined in experience; but only that they should 
be compatible with the possible existence of an 
object in space or time. In an act of logical 
judgment, one of the given concepts being always 
comprehended in the other, it is indifferent of 
what special attributes either is composed, pro- 
vided they possess sufficient clearness and dis- 
tinctness to enable the mind to discern the relation 
between them. In an act of logical reasoning, 
the validity of the conclusion depends solely on 
the quantity and quality of the given premises ; 
without any reference to the particular terms of 
which they are composed. In all, so long as the 
formal relation of the data remains the same, the 
matter may be changed as we please, without 
affecting the logical value of the thought In 
mixed thinking, on the other hand, the matter is 
of principal importance. To determine that this 
or that object of conception actually exists, that 
this or that judgment is in accordance with expe- 
rience, that this or that inference is sufficiently 
probable to furnish a reasonable motive to action, 
we require to be guided by a knowledge of the 
nature and circumstances of the particular object 
in question. And it is for this reason that all ex- 
amples of logical thinking are better expressed by 
means of arbitrary symbols than of significant 

r2 



244 PROLEGOMENA LOGICA. 

terms ; not that it is in any case possible to think 
without some matter or other, but because it is 
wholly indifferent what matter we may at the time 
be thinking about ; and, therefore, by employing 
an unmeaning sign, indifferently representative of 
any object of thought, we are enabled to clear the 
process from any accidental admixture of material 
knowledge, and to exhibit the form alone in its 
proper relation to the laws of thought. 

In accordance with the view here given of Form 
and Formal Processes, it will be proper to modify 
slightly some of the definitions of Logic given by 
those philosophers, whose views have been prin- 
cipally followed in the present work. Logic, to 
omit less accurate views of its nature, has been 
defined as the Science of the bare Form of Thought 1 , 
or as the Science of the Formal Laws of Thought k ; — 
definitions which, though substantially approaching 
far nearer to the truth than any antagonist view, 
still leave something to desire in point of verbal 
accuracy. The term formal strictly belongs rather 
to the process of pure thinking than to the laws by 
which it is regulated, or to the science which takes 
cognisance of them ; and Logic is not the science 
of the Forms of Thought in general, but only of 
such as are subservient to other processes of formal 
thinking. Other forms, such as modality, fall 
without the province of Logic, and within that of 

1 Kant, Logik, Einleitung i. Hoffbauer, Logik, §. 17. 
k Sir W. Hamilton, Edinburgh Beview, No. 115, p. 194. 



PROLEGOMENA LOGICA. 245 

Psychology; to which latter science, indeed, all the 
forms and laws of thought belong in their relation 
to the constitution of the thinking subject. To 
Logic, on the other hand, belong the same forms 
and laws in relation to those acts and products 
of pure thinking which are suggested by the one 
and governed by the other. If, therefore, slightly 
altering the language of the above definitions, we 
define Logic as the Science of the Laws and Pro- 
ducts of Pure or Formal Thinking 1 , we shall 
express with tolerable accuracy its character and 
province, according to the views advocated in the 
preceding pages. 

1 This coincides nearly with the definition given by Sir W. 
Hamilton, Beid's Works, p. 698, the science of the laws of thought 
as thought. 



CHAP. VIIL 

ON POSITIVE AND NEGATIVE THOUGHT, 

Logic has been described by Kant as the science 
of the necessary laws of the understanding and of 
the reason. Psychologically, the propriety of this 
division of the mental faculties has been called in 
question by eminent critics a . And in a logical 
point of view it is untenable, if, as I have endeavoured 
to shew, judgment and reasoning, in so far as they 
are logical processes, are both governed by the 
same laws, and must be referred to the same 
faculty. In the present chapter, however, it is 
proposed to examine another expression of the 
same definition, and to enquire in what sense the 
Laws of Thought can properly be called necessary. 
Kant employed this term to distinguish the laws 
of thought in general from those of thought as 
employed upon any definite class of objects ; it 
being optional with every man, and therefore con- 
tingent, whether he shall exercise his understand- 

a Among others by Sir William Hamilton, Edinburgh Review, 
No. 99, p. 205. and by M. Cousin, Lemons sur la philosophie de 
Kant, L. vi. 



PROLEGOMENA LOGICA. 247 

ing on one class of objects rather than another \ 
This distinction I have preferred to express in 
other words, by separating pure or formal from 
mixed or material thinking ; but the Kantian 
phraseology may serve to introduce a subject, the 
right understanding of which is of considerable 
importance in Logic : the difference, namely, be- 
tween positive and negative thinking. The phrase 
necessary laws of thought, if such language is allow- 
able, ought to imply that we cannot think at all 
except under their conditions : and yet it is notorious 
that such laws are daily transgressed, that nothing 
is more common than illogical reasoning. To 
reconcile the language with the fact is the object 
of the following observations. 

Illogical reasoning may be of two very different 
kinds. It may violate the laws of thought in cases 
where they are applicable, or it may endeavour to 
extend them to cases where they are not applicable. 
The offence in the former case consists in attempt- 
ing to draw a conclusion opposed to that which 
the laws require ; in the latter, in attempting to 
draw a conclusion where none can be legitimately 
inferred. Thus we may, verbally at least, reason, 
" All A is B ; all C is A ; therefore no C is B." Or 
we may reason, " All A is B ; some C is not A ; 
therefore some C is not B." If the laws of thought 
are in the strict sense necessary, i. e. obligatory 
upon every act of thinking, it will follow that these 
b Kant, Logik, Einleitung, I. 



248 PROLEGOMENA LOGICA. 

supposed reasonings are neither of them acts of 
thought at all. 

It is, of course, always possible to compose a 
verbal representation of a thought in which the 
rules of Logic shall be violated, and to understand 
fully the meaning of each word of which it is 
composed. The test, however, of the reality of a 
thought does not lie in the possibility of assertion, 
but in the possibility of conception* ; in the power, 
that is to say, of combining the given attributes in 
a single image representative of an individual object 
of intuition d . I may make use of the words a 
round square, or a bilinear figure ; but the terms 
imply no conception, because the attributes cannot 
be united in an image. These words therefore are 
not the signs of thought, but only express the 
negation of any object on which thought can be 
exercised 6 . 

And such, in ultimate analysis, will be seen to 
be the case with all verbal combinations in which 
the laws of formal thinking are violated ; whether 
directly, by denying their authority in cases to 

c Ov yap 7rp6s rbv e£co \6yov rj aTrobei^is, aWa 7rpos rbv iv rfj ^1^77 
C7T61 ovde crvWoyicrpos. Ae\ yap eariv ivarrjvai irpbs rbv e£co \6yov, 
aXka 7rpbs rbv ecrco \6yov ovk dei. Arist. Anal. Post. I. 10. 6. 

d It will be necessary here to bear in mind what has been 
observed before, that all conception implies imagination, 
though all imagination does not imply conception : see ante, 
p. 24. 

e See on this subject an excellent note in Sir W. Hamilton's 
edition of Reid, p. 377. 



PROLEGOMENA LOGICA. 249 

which they are applicable, or indirectly, by attempt- 
ing to apply them to cases where they are not 
applicable. The only difference between these two 
offences is, that in the former case the product is 
no thought whatever ; in the latter, it is not that 
kind of thought which it professes to be, 

Let us suppose, for example, a syllogistic con- 
clusion verbally asserted, the reverse of that which 
the laws of thought require ; such as, "All A is B, all 
C is A, therefore some C is not B." This reasoning 
supposes the possibility of conceiving a C, which 
shall at the same time be B and not B. Tried by 
this test, the form of words is ascertained to be 
representative of no thought at all. 

On the other hand, in a case where the law of 
reasoning is not applicable, as in the apparent syllo- 
gism ; " All Y is [some] Z, no X is [any] Y, there- 
fore no X is [any] Z," the thought is annihilated as a 
syllogism only : as a mere judgment, the concluding 
proposition may or may not be true ; and there is 
no impossibility in conceiving an X which is neither 
Y nor Z. But as a syllogism, it maintains that 
X is not Z, because it is not Y ; in other words, 
that nothing which is not Y can be Z, or that all 
Z is Y ; — an assertion which again involves a con- 
tradiction of the major premise, which, in asserting 
that all Y is some Z only, implies at the same time 
that some Z is not Y. This contradiction is not 
so apparent in the ordinary form of the affirmative 
proposition, in which the predicate is expressed as 



250 PROLEGOMENA LOGICA. 

indefinite, though thought as particular : and thus 
the elliptical and imperfect language of common 
Logic has caused to be overlooked the important 
truth, that illogical thinking is in reality no thinking 
at all. 

The language of this chapter may recall to the 
mind of the reader a distinction made in an earlier 
portion of the present work, between positive and 
negative ideas. A comparison of the two cases will 
serve to shew, that the expression negative thinking, 
or negation of thought, is properly applicable to 
both ; though in different relations and on different 
grounds. Positive thinking implies two conditions : 
firstly, the material condition, that certain attri- 
butes be given as united in a concept : secondly, 
the formal condition, that the concept be capable 
of individualization ; i. e. that the attributes be such 
as can coexist, in an object perceived or imagined. 
If either of these conditions be wanting, we are 
deficient in the sine qua non of actual thought. A 
given form of words may thus in two different 
ways be void of a thought corresponding. We 
may be unable to conceive separately one or more 
of the attributes given, or we may be unable to 
conceive them in combination. The former is the 
case, when we have never been personally conscious 
of the said attribute as presented ; the latter is the 
case, when the several presentations are incom- 
patible with each other. 

From defect in the first of these conditions, 



PROLEGOMENA LOGICA. 251 

a man born blind may be said to have a negative 
idea of colour in general ; and any man, to have 
a negative idea of a colour which he has not seen. 
The blind man may be able to distinguish a sphere 
from a cube by touch ; but if he is told that the 
ball which he has in his hand is white, he cannot 
connect the word with any sensation of which he 
has been at any time conscious. And in like 
manner, a man who has seen white objects only 
has no idea of red ; he knows it only as some 
colour which he has not seen. In this manner 
it is that we have negative ideas only of many of 
the objects on which men most boldly speculate. 
Such is the case with all our speculations on 
causality, as existing apart from the conscious 
exertion of power; on substance, other than as 
a conscious self; on consciousness in general, apart 
from the conditions of space and time. Of these 
we can only speak as a causality which is not our 
causality ; as a substance different from our sub- 
stance; as a consciousness unlike our conscious- 
ness^ The same is the case with all the specu- 
lations of our reason concerning the nature and 
attributes of an Infinite Being. By removing the 
condition of limitation, we remove the only con- 
dition under which such attributes have ever been 
presented to our consciousness. Further specu- 
lation is not thought, but its negation. 

The second condition fails in cases of illogical 

f Cf. Damiron, Psychologie, vol. ii. p. 221. 



252 PROLEGOMENA LOGICA. 

thinking, all of which may be shewn ultimately to 
annihilate themselves by involving a contradiction. 
And in these cases, the attempt to individualize 
the thought furnishes at once a decisive criterion 
of its negative character. In the former instances, 
the thought is only ultimately discovered to be 
unattainable, from the failure of every attempt to 
realize it : in the present case, the attributes can 
be immediately determined to be unthinkable, as 
mutually destroying one another. The former 
may be distinguished as materially or relatively 
negative, from the absence of the requisite data 
for thinking : the latter are formally or absolutely 
negative, as containing data which offend against 
the universal laws of human thought. The former 
might become positive, if man were furnished with 
a new sense or any additional faculty of intuition : 
the latter could only become so by a complete 
inversion of the existing constitution of his mind. 
The negative character of the first is shewn by 
Psychology, which ascertains empirically the limita- 
tions to which the mind is subject in the accu- 
mulation of materials for thinking : the negative 
character of the second is shewn by Logic, which 
lays down a priori the conditions to which all 
materials, whencesoever derived, must be subjected 
in the formation of thought. 

It is of the utmost importance to distinguish 
these two kinds of negative thinking, the material 
or psychological and the formal or logical, from 



PROLEGOMENA LOGICA. 253 

each other. No error in philosophy is more 
frequent in its occurrence, or more pernicious in 
its results, than a confusion on this point. Men 
are apt to mistake the absence of the materials for 
one thought for the presence of materials for its 
opposite; — to imagine that it is all one to be unable 
to think of an object as existing, and to be able 
to think of it as not existing; — to fancy that 
certain positions are condemned by the laws of the 
understanding, when the fact is only that their 
materials have not been given in an intuition ; — 
to suppose that to be rejected by reason, which 
in truth has never come in contact with reason 
at all. 

To examine in detail the prominent instances of 
the above confusion, which are plentifully exhibited 
by some of the so-called philosophers of the present 
time, would require a work of a higher and more 
controversial character than the present. I shall 
content myself with selecting two examples, one 
ancient and one modern, as specimens of the 
confident manner in which men of all ages, and 
under all religious systems, have been prone to 
dogmatize upon the highest matters of speculation, 
upon no better basis than the absence of all 
materials for speculating at all. 

Aristotle's well-known argument, to prove that 
the happiness of the Gods consists in contem- 
plation, is based on the ground that we cannot 
attribute to them moral attributes in the only way 



254 PROLEGOMENA LOGICA. 

in which such attributes come within the sphere 
of human consciousness ; viz. under the limitations 
and imperfections consequent upon human passion 
and human error. What scope, he asks, can there 
be for fortitude, where there is no pain to undergo ; 
or for temperance, where there are no evil desires 
to keep in check g ? But the reasoning is incom- 
plete. Cotta, in Cicero, pursuing the same prin- 
ciple to its ultimate consequences, shews clearly, 
that we must equally deny of the Deity the pos- 
session of any intellectual as well as of any moral 
quality. What is the object of reason and intel- 
ligence, but to gain a knowledge of that which is 
obscure ? What is the purpose of contemplation, 
but to gain a closer insight into the nature of the 
things contemplated ? Intellectual attainments 
have the same relation to human ignorance that 
moral virtues have to human frailty K 

The error of both these reasonings is the same : 
it consists in mistaking a psychological deficiency 
for a logical impossibility. To determine in thought 
that certain attributes cannot exist in any being 
except under given conditions of manifestation, it 
would be necessary that we should have had per- 
sonal experience of the abrogation of those con- 
ditions, and of the absolute destruction of the 
attributes in consequence. But such an experience 
in the present case is, ex hypothesis impossible ; the 

§ Eth. Nic. x. 8. 

h Cicero, De Natura Deorum, iii. 15. 



PROLEGOMENA LOG1CA. 255 

conditions being those to which the universal 
human consciousness is subject. To pronounce 
how consciousness exists in beings of a different 
nature from ourselves, it would be necessary that 
we should be capable of possessing their nature 
and faculties, as well as our own, and of comparing 
the two together, by the aid of a third power in- 
dependent of either. To pronounce that certain 
modes of consciousness cannot exist save as they 
exist to us, it is necessary that we should have 
personally tried every other possible relation of 
modes of consciousness to a conscious subject. 
Until human experience has extended thus far, to 
limit the province of faith by that of reason, — to say 
that what we cannot compass in thought we may not 
believe as existing, is to pass from criticism to 
dogmatism, a dogmatism resting its claim to dictation 
on a complete ignorance of the matter in which 
it dictates. 

The system of the great modern apostle of 
Atheism in Germany, Feuerbach, is based on a 
similar confusion. It assumes that the measure 
of what man is to believe is to be determined by 
what he can grasp in an act of positive thought : 
in other words, that the mere absence of the 
necessary data for thinking at all is tantamount to 
a logical determination of the non-existence of a 
corresponding object. God, according to this 
system, is but humanity deified in its intellectual, 
or moral, or physical attributes, according to the 



256 PROLEGOMENA LOGICA. 

varying condition,, characters, and wants of this or 
that people ; but in all, according to one form or 
another of Anthropomorphism. 

Falsehood is only dangerous from its possessing 
a certain portion of a mutilated truth. The one 
element of truth which underlies the Atheism of 
the Essence of Religion*, is the fact, that finite 
thought can only be positively exercised on finite 
objects. Thought, on its positive side, is ulti- 
mately tested by the individualization of concepts. 
To effect this, they must be referred to the repre- 
sentative image of some actual state of conscious- 
ness, — sensation, volition, affection, &c. In attempt- 
ing to grasp the Deity as an object of positive 
thought, — to speculate beyond what is revealed to 
us of the divine attributes as manifested in relation 
and accommodation to human faculties, man can 
only bring God down to his own level, and exercise 
his reason on those analogous attributes of which 
he has had experience in his personal conscious- 
ness. The error consists in overlooking the reli- 
gious feelings and affections, as a distinct class 
of psychological facts, coordinate with, not sub- 
ordinate to, the thinking faculty. The history of 
mankind in general, as well as the consciousness 
of each individual, alike testify that religion is not 

k With this work, and others of the same author, I am 
acquainted through the French translation by M. Ewerbeck, 
entitled, Quest-ce que la Religion d'apres la nouvelle philosopMe 
Allemande. 



PROLEGOMENA LOGICA. 257 

a function of thought ; and that the attempt to 
make it so, if consistently carried out, necessarily 
leads, firstly to Anthropomorphism, and ultimately 
to Atheism. 

The incompetency of such reasoning to prove 
its conclusion is manifest from the fact, that the 
mental phenomena on which alone it rests, 
must, from the nature of the case, be precisely 
the same, whether that conclusion be true or false. 
If human thought is subject to laws and limit- 
ations, formal and material, the mode and the 
sphere of positive thinking must be such as those 
laws and limitations require, whether there exist 
objects beyond it or not. But the hypothesis, 
indispensable to the rationalist, that the sphere of 
thought and that of being are coextensive, fails 
altogether to account for the phenomenon of 
negative thinking ; to explain, that is, how it can 
be that man, in the exercise of thought, ever 
finds himself encompassed with conditions and 
restrictions, which he is ever striving to pass and 
ever failing in the effort ; that he ever feels him- 
self in the presence of yearnings unsatisfied and 
doubts unsolved ; — yearnings which countless ac- 
cessions to the domain of thought have left as 
vague and restless as before ; — doubts which cen- 
turies of speculation have made no progress 
towards answering. These and such like humi- 
liating truths, altogether inexplicable on the 
arrogant assumption of a human God contem- 

s 



258 PROLEGOMENA LOGICA. 

plating the products of his creative intellect 1 , are 
the natural and necessary features of our position, 
if we believe that man, as individual or as species, 
is but a lower intelligence in the midst of the works 
of a higher, a being of finite intuitions, surrounded 
by partial indications of the Unlimited, of finite 
thought, contemplating partial revelations of the 
Incomprehensible. 

1 " Ueber die Natur philosophiren," says Schelling, " heisst 
die Natur schaffen." 

" Die Logik," says Hegel, " zeigt die Erhebung der Idee zu 
der Stufe von daraus sie die Schopferin der Natur wird." In 
the same spirit, Logic is declared to be, " Die Darstellung 
Gottes, wie er in seinem ewigen Wesen vor der Erschaffung 
der Natur und eines endlichen Geistes ist." 

The mock thunder of Salmoneus was modesty itself to 
this. 



CHAP. IX. 

OF LOGIC AS RELATED TO OTHER MENTAL SCIENCES. 

A division was early established in philosophy 
between the Logica docens, and the Logica utens; 
the one concerned with the pure laws and forms 
of thought, the other with the application of 
thought to this or that object matter. The 
relations of the latter it is not my present purpose 
to examine. Every art or science, in so far as it 
contains reasonings on its own special objects, 
may be regarded as furnishing an instance of the 
Logica utens; and in this point of view, Logic has 
no special affinity with one branch of knowledge 
rather than another. But in relation to the Logica 
docens, there are three branches of science, real or 
apparent, which, from community of object and 
method, as well as from historical connection, 
demand a more special consideration. 

The three sciences in question are Grammar, 
Psychology, and Metaphysics. Rhetoric, from 
an association with Logic and Grammar in the 
mediaeval Trivium, might also be thought to have 
a special claim on our attention. But, in truth, 
Rhetoric is connected by community of object- 

s 2 



260 PROLEGOMENA LOGICA. 

matter rather with the art of Dialectic, as exhi- 
bited in the Topics of Aristotle and the Probable 
Syllogisms of the Scholastic Logic, than with the 
formal science as treated of in the present work. 
Its relation to the latter is only by way of appli- 
cation, inasmuch as logical forms may be applied 
in rhetorical exercises; — a relation which reduces 
it to a level with any other employment of the 
Logica utens. With Psychology, indeed, its con- 
nection is far more intimate, but on the opposite 
side from that by which the same science is 
related to Logic. Logic, as the science of the 
laws and products of the understanding, is related 
to Psychology through the medium of the spe- 
culative and discursive faculties. Rhetoric, as 
concerned with the movement of the will, is 
related on the side of the emotional and prac- 
tical faculties, and is thus correctly described by 
Aristotle as an offshoot of Dialectic and Moral 
Philosophy. 

On the other hand, Psychology, Metaphysics, 
and Grammar, are intimately connected with the 
faculties, the laws, and the instruments of the 
universal process of thought, — a connection which 
has been recognised with more or less clearness 
from the origin of Logic to the present time. 
The Categories, from the days of Aristotle down- 
wards, have been disputed ground between Logic 
and Metaphysics, and are treated of by the 
Stagirite himself in connection with both sciences. 



PROLEGOMENA LOGICA. 261 

The treatise irepl epixrjveias, whose title, sorely 
misnomered by various translators, might be 
adequately expressed in English by, " of Lan- 
guage as the interpretation of Thought a ," is, in 
the early portion, devoted to grammatical defini- 
tions and distinctions. Psychology also, though 
less prominently introduced, claims her share in 
the multifarious matter of the Organon ; in the 
account of the processes of sensation, memory, 
and experience, as subsidiary to induction. 

Were we indeed to start from the whole Organon 
of Aristotle, as an uniform treatise on a single 
subject, it would be difficult to accommodate its 
contents to any modern classification of the mental 
sciences. But it may fairly be questioned, whether 
even the authority of the philosopher himself can 
be adduced in support of such a proceeding. While 
we cannot help admitting, with Sir William Hamil- 
ton 5 , that the incorrect notions which have pre- 
vailed, and still prevail, in regard to the nature and 
province of Logic, are mainly to be attributed to 
the authority of the father of the science, it may 
be doubted how far that authority has been put to 
a legitimate use by his followers. The same 



a For various interpretations of Interpretation, see M. St. 
Hilaire, De la Logique d'Aristote, p. i. ch. 10. The version 
given in the text corresponds to that by Isidore of Seville : 
" Omnis elocutio conceptse rei interpres est : hide periher- 
meniam nominant quam interpretationem nos appellamus," 

b Edinburgh Eeview, No. 115, p. 211. 



262 PROLEGOMENA LOGICA. 

eminent critic to whom we have just referred has 
observed in another place, that there is required 
for the metaphysician not less imagination than 
for the poet; that it may, in fact, be doubted 
whether Homer or Aristotle possessed this faculty 
in greater vigour c . The two authors here placed 
in juxtaposition may be compared in more respects 
than that of their mental powers. The influence 
of Homer in Poetry has been similar to that of 
Aristotle in Philosophy; yet, while, from the 
Father of Criticism to the present day, there has 
never been wanting a champion to maintain against 
all impugn ers the unity of design of the Iliad, 
and its exact relation to a beginning, a middle, and 
an end, the primary argument of this "" one entire 
and perfect chrysolite" has been almost as much 
disputed among critics as the question of the 
definition of Logic. Different portions of the poem 
have been pronounced genuine or spurious, accord- 
ing to this or that conception of the poet's design ; 
and, finally, it has even been maintained that the 
model of all succeeding Epics is little more than a 
fortuitous concourse of atoms, the fragments of 
distinct rhapsodists. The Organon of Aristotle 
has had a similar fate. Various have been the 
conjectures concerning its design and method. 
Portions have been at different times regarded as 
logical, as grammatical, as metaphysical ; nor have 
there been wanting critics to deny the genuineness 

c Reid's Works, p. 99. 



PROLEGOMENA LOGICA. 263 

of this or that part. The parallel might be carried 
further. The different portions of the Iliad are 
said to have been collected and arranged in the 
time of Pisistratus, about 340 years after the date 
assigned by Herodotus, (rightly or wrongly,) to 
the birth of the poet ; and the writings of Aristotle 
are generally supposed to have received their present 
form and arrangement at the hands of Andronicus 
of Rhodes, a philosopher who flourished about 
three centuries later than the Stagirite. I am not 
indeed aware that any critic has been bold enough 
to maintain a thoroughly Wolfian hypothesis of 
the origin of the Organon ; and yet there are not 
wanting grounds on which a not very different 
theory might be supported ; not indeed as regards 
the authorship, but certainly as regards the unity 
of design of the work. The title by which the 
collected treatises are known is undoubtedly of 
recent origin : it is not found in Aristotle himself, 
nor in any of his earlier commentators ; and, as far 
as existing evidence can determine, it appears not 
to have been in common use before the fifteenth 
century d . The several treatises themselves are 
invariably mentioned by their author as distinct 
works under distinct titles ; and even after the time of 
Andronicus, commentaries were generally written, 
not on the Organon as a whole, but separately on 
its constituent parts. If from the books we turn to 
the matters of which they treat, the result is the 

d St. Hilaire, De la Logique cVAristote, vol. i. p. 19. 



264 PROLEGOMENA LOGICA. 

same. Logic, as the name of an Art or Science, 
does not once occur in the writings of Aristotle; 
and the cognate adjective and adverb are used in a 
peculiar and much more restricted sense than that 
which has subsequently been given to them. The 
names sanctioned by the Philosopher himself, such 
as Analytic and Dialectic, are commensurate with 
portions only of the Organon ; the division of 
Philosophy into Logic, Physics, and Ethics, adopted 
by the Stoics, and sometimes attributed (on ques- 
tionable grounds) to Plato, receives no sanction 
from the Stagirite: indeed, he adopts a classifi- 
cation in many respects at variance with it, dis- 
tinguishing theoretical philosophy from practical 
and productive, and dividing the first into three 
branches, Physics, Mathematics, and Theology 6 . 

Leaving then altogether the question of autho- 
rity, and adopting the formal view of Logic taken 
in the preceding pages, as the only one which 
promises to secure for the science what it has so 
long needed, an exact definition and a determined 

e Metaph. v. 1. Mr. Karslake (Aids, p. 10.) speaks of the 
Organon as presenting so coherent a system, that the assertion 
that it contains a few only of Aristotle's logical works is 
doubtful. To me there appears little more of coherence 
than may naturally be expected in distinct writings of the 
same author on any question of Grammar, Analytic, Dialectic, 
or Khetoric. And, as far as we can conjecture from existing 
evidence, it is most probable that the several books were 
written in the reverse order of that in which they are now 
arranged. See Fries, System der Logik, p. ]5. 



PROLEGOMENA LOGICA. 265 

field of inquiry, I shall proceed to examine the 
relation in which Logic, as thus exhibited, stands 
towards the cognate sciences of Psychology, 
Grammar, and Metaphysics. 

Of Psychology something has already been said 
in the earlier portion of the present Essay. Logic 
deals with the products of the several thinking 
acts, with concepts, with judgments, with reason- 
ings, as, according to certain assumed laws of 
thinking, they ought to be or not to be f . It is 
competent to test the validity of all such products, 
in so far as they comply or not with the conditions 
of pure thought ; leaving to this or that branch of 
material science to determine how far the same 
products of thought are guaranteed by the testi- 
mony of this or that special experience. Thus it 
accepts, as logically valid, all such concepts, judg- 
ments, and reasonings, as do not, directly or in- 
directly, imply contradictions ; pronouncing them 
thus far to be legitimate as thoughts, that they do 
not in ultimate analysis destroy themselves. That 
they will be also accepted upon an appeal to expe- 
rience, it does not decide ; it only recommends 

f " Die ganze reine Logik hat es mit Verhaltnissen des 
Gedachten, des Inhalts unserer Vorstellungen (obgleich nicht 
speciell mit diesem Inhalte selbst) zu ttmn ; aber uberall 
nirgends mit der Thdtigkeit des Derikens, nirgends mit der 
psycliologischen, also metaphysischen, Moglichkeit desselben." 
Herbart, Psychologie als Wissenschaft. Th. II. §. 119. 



266 PROLEGOMENA LOGICA. 

them as qualified for further examination. It is 
thus competent to determine the possible existence 
of a class of objects corresponding to a given 
concept, the necessary truth of an analytical, and 
the possible truth of a synthetical judgment, the 
formal validity of a conclusion as necessarily fol- 
lowing from certain assumed premises. Questions 
concerning the real existence of this or that class 
of objects, the actual truth of a synthetical judg- 
ment, or of a conclusion out of relation to its given 
premises, it sends up for judgment to the tribunal 
of Experience. 

As Experience decides on the relations of any 
given product of thought to the actual phenomena 
presented by this or that object of intuition, so 
Psychology decides on its relations to the actual 
constitution of the human mind. Why it is that 
the laws of pure thinking extend thus far and no 
farther; — what are the mental processes preliminary 
and subsidiary to thought, and the nature of the 
thinking act itself as giving rise to the logical 
products ; — whence arises the phenomenon of ille- 
gitimate thinking ; — the nature and origin of various 
impediments and errors to which thinking and 
other mental acts are subjected in mankind; — the 
relation of the several mental acts to one or more 
faculties of mind, and the value of such distinction 
as absolute or relative, implying a notional only, 
or an actual separability; — in short, all inquiries 



PROLEGOMENA LOGICA. 267 

into the actual phenomena of man's mental con- 
stitution and their explanation form the object- 
matter of Psychology g . 

From this it appears, that Psychology, as well 
as Physical Science, is, in the widest sense of the 
term, empirical. It inquires, that is to say, what 
are the actual phenomena of the several acts and 
states of the human mind, and the actual laws or 
conditions on which they depend; and in this 
sense the laws of thought themselves are empirical 
and within the province of Psychology ; inasmuch 
as it is a matter of fact and experience that men 
do reason according to them. Logic, on the other 
hand, can in no sense be called empirical, inasmuch 
as the actual constitution, whether of the world 
within or of the world without, is assumed indeed 
and implied in its researches, but in no respect 
described or investigated. We are not to ascertain, 
as a matter of fact, that men do reason in this or 
that form, as governed by this or that law ; but, on 
the assumption of certain laws, we are to determine 
a priori the forms which legitimate thinking ought 
to exhibit, whether mankind in general do comply 
with them or not h . Logic is indeed ultimately to 
be referred to the test of experience ; but only in 

s Much of this is distinguished by Kant as Applied Logic, 
which however he allows to be more properly referred to 
Psychology. 

h Kant, Logik Einleitung II. 4. Drobisch, Neue Darstellung 
der Logik, §.9. 



268 PROLEGOMENA LOGICA. 

respect of its conformity with facts without its 
province, not in respect of the coherence of its 
parts within. So far as it implies that, as a matter 
of fact, men do reason in syllogisms, so far its 
pretensions may be tested by reference to the 
empirical truths of Psychology. So far as it asserts 
that the legitimate forms of the syllogism are such 
and such, it is simply deductive a priori, and 
necessarily valid for any class of thinking beings 
whose laws are such as it presupposes. An empi- 
rical science may contain much partial truth, though 
omitting many important phenomena and erro- 
neously accounting for many which it recognises. 
It offers much, therefore, for enlarged experience 
gradually to supply and correct. An a priori 
Science, like Logic, is tested by experience only 
with reference to its fundamental hypotheses. If 
these are accepted, they carry with them the whole 
superstructure of details. If these are rejected, 
every portion of the science falls to the ground 
along with them. 

But though Logic and Psychology have thus 
each their respective provinces and methods, it 
cannot be too often repeated, that neither can be 
taught as a science efficiently and satisfactorily, 
unless in connection with the other. We may 
learn by rote a multitude of logical rules, and 
fondly imagine that we are acquiring an art 
which will enable us to think ; — a course of Logic 
being in fact about as necessary for making men 



PROLEGOMENA LOGICA. 269 

thinkers, as a course of Ethical Philosophy for 
making them honest, or a course of Optics for 
enabling them to see. Or we may analyse in 
dictione and extra dictionem all sorts of imaginary 
fallacies propounded by imaginary sophists, and 
dream that we are forging an impenetrable pano- 
ply against all the deceits of the world ; — as if we 
could bind men down in heavy securities to lie 
and cheat by rule, in order that they may be 
detected in due course of art. Or we may draw 
up syllogisms in orthodox mood and figure and 
babble about Laws of Thought, and never dream 
of asking, what is the nature of Thought as a 
process, and with what elements does it combine 
in the actual formation of this or that compound. 
Or, on the other hand, starting from confused or 
erroneous notions of the nature and powers of the 
human mind, we may blame Logic for not accom- 
plishing what no science can accomplish, and 
deem its whole contents a tissue of jargon and 
imposture, because it is neither able to open a 
Royal Road to the Encyclopaedia, nor to convert 
natural folly into supernatural wisdom. It may 
safely be asserted, that nine tenths of the mistaken 
judgments to which Logic has been subjected on 
the part of friends and adversaries, unreasonable 
eulogy on the one hand, equally unreasonable 
abuse or contempt on the other, have been owing 
to its treatment out of relation to psychology, — to 
its having been expounded and studied without 



270 PROLEGOMENA LOGICA. 

any preliminary attempt to ascertain what are the 
nature and limits of the thinking faculty and what 
character its laws and products ought to exhibit 
in conformity with the constitution of the human 
mind. 

With Grammar, Logic is connected through the 
medium of the universal instrument of thought, 
Language. The practical necessity of this instru- 
ment for the formation as well as for the com- 
munication of thought, has been noticed already : 
it remains to inquire in what different ways this 
their common object is dealt with by Logic and 
Grammar respectively. Universal Grammar, with 
which alone we are concerned, (the history and 
idiomatic peculiarities of special languages being 
obviously unconnected with general Logic,) has 
been happily defined as " the science of the rela- 
tions which the constituent parts of speech bear 
to each other in significant combination 1 ." It is 
thus concerned with Language primarily and es- 
sentially ; Logic, secondarily and accidentally. The 
former has given certain articulate sounds, to find 
their relation to certain supposed counterparts in 
thought. The latter has given to determine the 
necessary relations of concepts to each other; but 
in so doing it is compelled secondarily to exhibit 

1 Sir John Stoddart, Philosophy of Language, pt. i. p. 21. 
Universal Grammar is properly a science, particular Gram- 
mar an art, as is observed by Du Marsais, Encyclopedic, Art. 
Grammaire, p. 842. 



PROLEGOMENA LOGICA. 271 

the corresponding relations of the sounds by which 
concepts are represented. 

The two sciences differ also in the extent of 
their provinces. Logic considers language simply 
as the instrument and representative of thought. 
Grammar will include its relation to intuitions and 
emotions and every state of consciousness which 
finds its expression in speech k . Logic considers 
language only in so far as it is indispensable to 
thought, and accordingly analyses speech only to 
that point at which it is representative of the 
simplest element of thought, the concept. Any 
parts into which a concept may be divided, which 
are not themselves concepts, are beyond its pro- 
vince, as not being representative of a complete 
thought, nor competent instruments alone for the 
performance of an act of thinking. Hence all syn- 
categorematic words, as not being per se significant, 
are not recognised by Logic. 

In Grammar, the unit of thought is a judgment, 
both terms being necessarily represented by words. 
Hence the unit of speech in Grammar is a pro- 
position ; the office of the subordinate parts of 
speech being to limit or connect the primary parts 
as subjects or predicates of a given assertion 1 . 

k See Harris, Hermes, cli. iii. 

1 For a further illustration of this doctrine, not universally 
held by Grammarians, the reader is referred to an article by 
the present author, on the Philosophy of Language, in the 
North British Review, No. 27. 



272 PROLEGOMENA LOGICA. 

Such connections and limitations may be more 
conveniently effected by the invention of words 
expressive of relations between concepts, than 
by the use of distinct signs for every new con- 
cept resulting from such relations : this however 
is one of the luxuries only, not one of the 
necessaries of language, and, as such, is not 
noticed by Logic. Viewed simply as an element 
of thought, it is indifferent whether the same 
concept be expressed by a combination of sub- 
stantive and adjective, as in the English " four- 
footed beast," or the German " vierfiissiges Thier," 
by the interposition of a preposition, as in the 
French " bete a quatre pieds," or by a single sub- 
stantive, such as the classical equivalent, " qua- 
druped." 

In Logic, the unit of thought is also a judg- 
ment, but not one which requires a verbal repre- 
sentative of both its constituent parts. Conception, 
the simplest act of thought, consists in the referring 
a given concept to possible objects as imagined. 
Here there is, in the psychological sense of the 
term, a judgment; i. e. a consciousness of the pre- 
sence of the objects in thought; but that con- 
sciousness does not form an additional concept, 
nor require as its necessary exponent a second 
verbal sign. Hence the unit of speech in Logic 
is a term ; such being a sufficient verbal instrument 
for the performance of the first and simplest act of 
thought. 



PROLEGOMENA LOGIGA. 273 

With reference to the second operation of 
thought, judgment, wherein the two sciences 
come most nearly into contact, the following 
distinction is important. Grammar considers 
words objectively, as signs of things. Hence the 
distinction of tenses, according as the remote or 
represented object is considered as contempora- 
neous with, or distant in time from, the speaker. 
Logic considers words subjectively, as signs of 
thoughts. Hence the only logical tense is the 
present, the immediate or presented objects being 
necessarily contemporaneous with the act of con- 
sciousness by which they are now thought in 
conjunction m . 

It is sometimes said that Logic recognises two 
only of the grammatical parts of speech, the noun 
and the verb, forming the two terms of the pro- 
position, with and without time 11 . It would be 

m See ante, p. 63. 

n " Grammatici enim, considerantes vocum figuras, octo 
orationis partes annumerant. Philosophi vero, quorum omnis 
de nomine verboque tractatus in significatione est constituta, 
duas tantum orationis partes esse docuerunt: quicquid plenam 
significationem tenet, siquidem sine tempore significat, nomen 
vocantes ; verbum vero, si cum tempore." Boethius, Int. ad 
Syll. (p. 561.) " Et sciendum est quod Dialecticus solum 
ponit duas partes orationis, scilicet nomen et verbum. Alias 
autem omnes appellat syncategorematicas, id est consigni- 
ficativas." Petr. Hisp. Sum. Log. Tr. i. Here, as in the De 
Interpretation of Aristotle, the type of the logical proposition 
is theform distinguished as seeundi adjacentis, the verb being 
neither the copula alone, nor the predicate alone, but the 

T 



274 PROLEGOMENA LOGICA, 

more correct to say that Logic, viewing language 
in a different light from Grammar, and analysing 
on a different principle, does not recognise the 
grammatical parts of speech at all. The simplest 
elements of a complete assertion in Grammar are 
the noun and the verb ° ; the latter being a com- 
bmation of attribute and assertion. Hence the 
grammatical type of a proposition is that distin- 
guished in scholastic language as secundi adjacentis; 
and to this form, all varieties produced by the 
accidents of particular languages must, in Universal 
Grammar, be virtually reduced 5 . In Logic, on 
the other hand, for the purposes of opposition 
and conversion, as well as from the necessity of 
assigning a quantity to both terms of the pro- 
position, the type is required to be of the form 



combination of the two, however expressed. A neglect of 
this has misled many commentators and critics on Aristotle, 
from Ammonius to the present day. 

° " In all languages there are only two sorts of words 
which are necessary for the communication of our thoughts, 
the noun and the verb." Tooke, Div. of Purley, ch. 3. 

p Hence it follows that the copula is, grammatically speak- 
ing, no verb at all. It fulfils none of the functions of that 
part of speech, for it implies no attribute, and cannot, when 
united to a subject, form a complete assertion. In such a 
sentence as " the meadows are white with frost," the true 
verb is not the copula, but the copula with the adjective, are 
white, as may be seen by substituting the Latin, " prata canis 
albicant pruinis." Whether this can be expressed in one word 
or not, is an accident of this or that language, and is beyond 
the province of Universal Grammar, 



PROLEGOMENA LOGICA. 275 

tertii adjacentis; the subject and predicate being 
regarded as two given concepts, the objects of 
which are identified or distinguished by means of 
the copula. Hence, in every case in which the 
proposition is exhibited in its logical form, the 
grammatical verb will correspond, not to any 
single word in the proposition, but to a com- 
bination formed of the copula and the quantified 
predicate, — to all, in short, that is asserted of the 
subject. The predicate concept may thus, in 
different points of view, answer to two distinct 
grammatical relations. Taken by itself, it is a 
noun, identified in certain respects with another 
noun as the subject. Taken in its predicate 
character, it forms a portion of the verb, the 
remainder being supplied by the copula. Those 
logicians who maintain the copula to be the 
logical verb, confound the accidents of particular 
languages with the essentials of language in general 
as a sign of thought. With them the verb is 
determined solely by the subordinate feature of 
its personal inflection, not by the primary charac- 
teristic of its signification. 

With regard to the relation of Logic to Meta- 
physics, some preliminary verbal explanation is 
necessary, owing to the various senses in which 
the latter term has been used. Among modern 
philosophers, empirical psychology, which the 
ancients regarded as a branch of physics q , is 
i See Hamilton on Eeid, p. 216. 

t2 



276 PROLEGOMENA LOG1CA. 

frequently classified as metaphysical. Thus the 
contributions of Reid and Stewart to the inductive 
science of the human mind are not unfrequently 
spoken of as Scotch Metaphysics ; a nomenclature 
which the latter of these philosophers has in some 
degree sanctioned by his own writings 1 . Such a 
classification is, however, inconsistent with the 
fundamental doctrines of the Scottish School. It 
has been before observed that one of their leading 
principles is, that in the investigation of mind as 
well as of matter, phenomena alone are the legi- 
timate objects of science ; the substance and 
essential nature of both being beyond the reach 
of human faculties. Whereas Metaphysics has 
from the earliest days been distinguished as the 
Science of Being as Being, in opposition to all 
inquiries into the phenomena exhibited by this or 
that class of objects 5 . How far such a problem 
is capable of solution is another question ; but the 
mere propounding of it implies an object totally 

r For instance : " Nothing contributes so much to form 
this talent, as the study of Metaphysics ; not the absurd 
Metaphysics of the Schools, but that study which has the 
operations of the mind for its object." Elements, vol. i. ch. 2. 
In other places, Stewart has noticed this phraseology as a 
loose use of language, and has attempted to account for it. 
But the term ought never to have been used at all. 

s Arist. Metaph. iii. 1. "TLvtiv emo-Tripr) ns rj decopet to ov rj ov kcu 

to. tovtco virapxovTa Kaff avro. The name Metaphysics is of much 
later date, but its object has always been regarded as identical 
with that distinguished by Aristotle as First Philosophy, or 
Theology. Cf. Wolf, Ontologia, §. 1. 






PROLEGOMENA LOGICA. 277 

distinct from that of an inquiry into the faculties 
and laws of the human mind. 

The object of the older Metaphysics has been 
distinguished in all ages as the one and the real, 
in opposition to the many and the apparent*. 
Matter, for example, as perceived by the senses, 
is a combination of distinct and heterogeneous 
qualities, discernible, some by sight, some by smell, 
some by touch, some by hearing. What is the 
thing itself, the subject and owner of these several 
qualities, and yet not identical with any one of 
them ? What is it by virtue of which these several 
attributes constitute or belong to one and the 
same thing ? Mind, in like manner, presents to 
consciousness so many distinct states and ope- 
rations and feelings. What is the nature of that 
one mind, of which all these are so many modifi- 
cations ? The inquiry may be carried higher still. 
Can we attain to any single conception of Being 
in general, to which both Mind and Matter are 
subordinate, and from which the essence of each 
may be deduced u . 

Ontology, as thus explained, may be treated in 
two different methods, according as its exponent 
is a believer in to bv or in tol ovra, in one or 
in many fundamental principles of things. In 
the former, all objects whatever are regarded as 

* Arist. Metaph. iii. 2. 

u Wolf, Phil. Bat. Disc. Pral. §. 73. Herbart, Allgemeine 
Metaphysik, §. 27. 



278 PROLEGOMENA LOGICA. 

phenomenal modifications of one and the same 
Substance, or as self-determined effects of one and 
the same Cause. The necessary result of this 
method is to reduce all metaphysical philosophy 
to a Rational Theology, the one Substance or 
Cause being identified with the Absolute or the 
Deity. According to the latter method, which 
professes to treat of different classes of Beings 
independently, Metaphysics will contain three 
coordinate branches of inquiry, Rational Cosmo- 
logy, Rational Psychology, and Rational Theo- 
logy v . The first aims at a knowledge of the 
real essence, as distinguished from the phenomena, 
of the material world; the second discusses the 
nature and origin, as distinguished from the facul- 
ties and affections, of the human soul and of 
other finite spirits x ; the third aspires to compre- 
hend God Himself, as cognisable a priori in his 
essential nature, apart from the indirect and relative 
indications furnished by his works, as in Natural 
Theology, or by his word, as in Revealed Religion. 
These three objects of metaphysical inquiry, God, 

v Herbart, Lehrbuch zur Philosophie, §.7. Allgemeine Meta- 
physik, §. 31. Anm. 

x " Man findet hier die Trennung der empirischen von der 
rationalen Psychologie ; die erste durchlaiift die einzelnen 
sogenannten Seelenvermogen ; die andre spricht iiber Natur 
und Urspmng der Seele, iiber Unsterblichkeit, Zustand nach 
dem Tode, Unterschied zwisehen den Seelen der Menschen, 
der Thiere, und den hoheren Geistern." Herbart, Allgemeine 
Metaphysik, §.29. 



PROLEGOMENA LOGICA. 279 

the World, the Mind, correspond to Kant's three 
Ideas of the Pure Reason ; and the object of his 
Critique is to shew that, in relation to all three, 
the attainment of a system of speculative philo- 
sophy is impossible. 

The former of these methods is the bolder and 
the more consequent ; and, moreover, the only one 
which can be consistently followed by those who 
believe in the possibility of a Philosophy of the 
Absolute. For, a plurality of real objects being 
once admitted as the highest reach attainable by 
human faculties, these must necessarily be regarded 
as related to, and limited by, each other. Accord- 
ingly, this method has been followed by the 
hardiest and most consistent reasoners on Meta- 
physical questions, by Spinoza under the older 
form of speculation, and by Hegel after the Kan- 
tian revolution. But thus treated, Metaphysical 
speculation necessarily leads to Pantheism; and 
Pantheism, at this elevation, is foj all religious 
purposes equivalent to Atheism y . The method is 

y It has of late been a favourite criticism of Spinoza to say, 
with Hegel, that his system is not Atheism but Acosmism : 
and this is true in a speculative point of view. But if I allow 
of no God distinct from the aggregate of the Universe, myself 
included, what object have I of worship? Or if, according to 
the later manifestation of Pantheism, the Divine Mind is but 
the sum total of every finite consciousness, my own included, 
what religious relation between God and man is compatible 
with the theory? And, accordingly, the Pantheism of Hegel 
has found its natural development in the Atheism of Feuer- 
bach. 



280 PROLEGOMENA LOGICA. 

thus condemned by its results; and the condemn- 
ation will not be retracted upon a psychological 
examination of its principles. Its fundamental 
conception is not thought, but its negation. The 
Thought which is identified with Being in general, 
is not my thought, nor any form of consciousness 
which I can personally realize V My whole con- 
sciousness is subject to the conditions of limitation 
and relation of subject and object. A system 
which commences by denying this relation, starts 
with an assumption concerning the possible cha- 
racter of an intelligence other than human, and con- 
sequently incapable of verification by any human 
being. Yet the system is the product of a human 
thinker, and addressed to human disciples. 

The second method of Metaphysical inquiry is 
less presumptuous, though perhaps also less con- 
sistent. It starts with the assumption of a plurality 
of Beings ; thus virtually abandoning the Philosophy 
of the Absolute. To the Theological portion of 
this system belong the arguments of Descartes 
and Clarke to prove a priori the Being and Attri- 
butes of God. To the Cosmological portion belong 
all inquiries into the substratum of sensible phe- 

z This is expressly stated by an eminent disciple of Hegel, 
who professes to discover in Aristotle's Metaphysics an anti- 
cipation of Hegelianism. " La pensee que nous venons de 
decrire est la pensee absolue. II ne s'agit pas ici de la pensee 
subjective, qui est une fonction psychologique restreinte a 
lame humaine." Michelet, Examen de la Metcqjhysique d'Aris- 
tote, p. 276. 



PROLEGOMENA LOGICA. 281 

nomena: and the Psychological portion includes, 
along with other branches of Pneumatology, those 
researches into the nature of the human mind, 
which treat of itself, not of its phenomena. Upon 
the theological discussion, I shall not enter here. 
The question of the relation of the human mind to 
religious intuitions is one of the most delicate and 
the most difficult in Psychology, and to treat it 
adequately would require a separate volume. On 
the two latter branches of Metaphysics, which 
Kant regarded as equally unattainable with the 
first, something has been said in a former chapter. 
It was the opinion of Kant, as well as of Reid and 
Stewart, that the subject of mental as well as of 
bodily attributes is not an immediate object of 
consciousness ; — in other words, that in mind as well 
as in body, Substance and Unity are not pre- 
sented, but represented. Those who accept this 
doctrine are only consistent in regarding metaphy- 
sical inquiry in all its branches as a delusion. 
But a philosophical examination is incomplete, 
unless it not only points out the truth, but 
likewise explains the cause of error. The weak 
point of the above doctrine is, that it fails in ex- 
plaining, on psychological grounds, how the sup- 
posed delusion originated. Experience furnishes, 
if not the cause, at least the occasion of every 
object of our cognition ; and, unless upon the sup- 
position that a knowledge of Unity and Substance 
is immediately given in one phase at least of con- 



282 PROLEGOMENA LOGICA. 

sciousness, it is impossible to account for its in- 
vention in any. The multifarious phenomena of 
internal as well as of external sense present, on 
the opposite hypothesis, nothing in any respect 
analogous to the substance to which they are attri- 
buted, — nothing that can operate in any way even 
as the occasional cause from which the existence 
of such a substance could be suggested. Metaphy- 
sical philosophy may contain much that is ground- 
less, much that is deceptive ; but the whole analogy 
of deception and hypothesis in other branches of 
speculation leads to the conviction, that it can 
only arise from rashly transferring to new relations 
ideas which are given in some relation or other. 

Instead, therefore, of considering the whole of 
Metaphysics to be based on a delusion, and its 
ultimate destiny to be utter extinction, we shall 
probably come nearer to the truth, if we regard 
its unsound portions as based on a perverted in- 
tuition, and anticipate that it will be finally ab- 
sorbed in that science to which the intuition in 
its original relation properly belongs. If, for 
example, it should ultimately be made manifest, 
that to the material world we have no relation, 
except through the various phenomena of sense; 
but that in the mental world, Self, as well as the 
phenomena of self, is an immediate presentation of 
consciousness, it will follow, that in the former we 
have no ground for maintaining the existence of 
things other than the phenomena presented ; and 



PROLEGOMENA LOGICA. 283 

that consequently, in this department, Ontology, as 
distinct from Phenomenology, is occupied solely 
with chimeras of our own invention : whereas 
Psychology, being called upon to extend its in- 
quiries from the phenomena of self to that of 
which they are phenomena, will legitimately in- 
clude the remaining portion of those problems 
which have hitherto been appropriated to Meta- 
physics. 

But this question cannot be discussed here. 
My present concern is only with the relation 
supposed to exist between Metaphysics, as above 
described, and Logic. In the earlier form of 
Metaphysics, which prevailed from Aristotle to 
Kant, an intimate connection was supposed to 
exist between the two sciences. The Principles 
of Contradiction and Excluded Middle, which have 
been exhibited in a former chapter as Laws of 
Thought, are found in the metaphysical as well as 
in the logical writings of Aristotle a ; and the former, 
together with that of Sufficient Reason, is placed 
by Wolf, the immediate predecessor of Kant, at the 
head of Ontology \ But after the Kantian Critique, 
this association was no longer possible. Kant 
shewed clearly that, without synthetical judgments 
a priori, Metaphysical science was impossible : 

a For the principle of Contradiction, see Arist. Metaph. iii. 
3. x. 5. Anal. Post. i. 11. For that of Excluded Middle, see 
Metaph. iii. 7. ix. 4. Anal. Post. i. 2. ii. 13. 

b Cf. Wolf, Ontologia, §. 27, 29, 56, 71, 498. 



284 PROLEGOMENA LOGICA. 

and this at once put an end to all attempts which 
had hitherto been made to elicit a science of Being 
from the laws of formal thinking which are the 
foundation of Logic. The two sciences, thus 
divorced, become apparently united again in the 
system of Hegel ; but the union is apparent only. 
For the Hegelian Logic is based, not on an 
acknowledgment, but on a defiance of the Laws 
of Thought. It is a Logic of the Reason, of 
which the fundamental position is, that the laws 
of the Understanding are applicable to finite objects 
only, and that Thought in relation to the infinite 
is free from their dominion. Logic thus returns, 
as regards its object, not to the Aristotelian 
Analytic, but to the Platonic Dialectic, as a 
science of the Real and the Absolute ; though 
the method pursued is opposed to Plato as much 
as to Aristotle c . On the other hand, in pro- 
portion as we adhere more closely to the formal 
view of Logic, the separation of that science from 
Metaphysics becomes more complete. An eminent 
advocate of that view, who is far from adopting 
Kant's opinion of the impossibility of Metaphysics, 
expresses his conviction of the very different objects 
and methods of the two sciences, by likening the 

c The Principle of Contradiction is acknowledged by Plato, 
as fully as by Aristotle. Cf. Phsedo, p. 103. c. 3wa>fxo\oyr)Kanev 

apa, ixr]be7TOT€ ivavriov iavrco to ivavrlov ecrecr&u. Of its abrogation 

in relation to the higher metaphysics we find no hint in either 
philosopher. 



PROLEGOMENA LOGICA. 285 

union of Metaphysics and Logic to a lecture on 
the Integral Calculus and the Rule of Three d . 
And there is much truth implied in this some- 
what overstrained comparison. With formal Logic, 
Metaphysics stands rather in opposition than in 
connection. The former is the science of the 
ultimate laws of the thinking subject ; the latter, 
of the ultimate realities of the objects about which 
we think. 

Metaphysical inquiry, if capable of a successful 
prosecution, may furnish a criticism or explanation 
of certain forms of thought assumed by Logic ; for 
a form of thought implies a certain relation between 
given objects, — a relation which might be further 
elucidated if the nature of objects in general could 
be satisfactorily determined. Thus we have seen 
that the form of logical judgments and reasonings 
contains by implication those negative notions of 
substance and cause, the investigation of which is 
the special object of metaphysical inquiries. The 
science of Metaphysics, therefore, if it could be 
constructed on a solid basis, would furnish a 
criticism of those principles which are tacitly 
acknowledged in every mental process. But for 
the purposes of formal Logic, such a criticism is 
not needed. It is sufficient for that science to 
accept the principles in the obscure form in which 
they are acknowledged by common thought and 

d Herbart, Lehrbuch zur Philosophie, Vorrede zur zweitei% 
Ausgabe. 



286 PROLEGOMENA LOGICA. 

common language ; especially as, being indifferently 
implied in sound and unsound thinking, they furnish 
no criterion by which we can distinguish the one 
from the other. 

This view is confirmed by the history of philo- 
sophy down to the present time. While Logic, from 
the days of Aristotle, has been in possession of a 
scientific method and a definite contents, whose 
truth, whatever opinion may be entertained of their 
utility, no critic has succeeded in impugning, 
Metaphysics has from the same period been equally 
conspicuous as the changing Proteus of philosophy, 
whose concealed wisdom, sought after by ceaseless 
efforts of strength and countless varieties of artifice, 
has invariably eluded the inquiries of his wor- 
shippers. The union of the two, so far from con- 
tributing to the scientific completeness of the 
former, has only served to mar its beauty and 
simplicity by extralogical details, and to misrepre- 
sent its true purpose and value by obscure intima- 
tions of deeper mysteries lying hid beneath its 
apparent surface. On the other hand, in propor- 
tion as the true character of Logic as a science 
has become better known and appreciated, it has 
gradually been separated from Metaphysics, and 
been associated with Psychology. As the science 
of the laws of thought, it is absurd to expect that 
its object and character can be rightly estimated by 
those who are unacquainted with the nature and 
powers of the understanding itself, — with its re- 



PROLEGOMENA LOGICA. 287 

lation to the cognate faculties and operations of 
the humanmind, — with its legitimate province and 
duties. It is only in this connection that we can 
hope to see Logic finally freed from the unsightly ex- 
crescences with which it has hitherto been deformed, 
yet still retaining a clearly defined portion of 
valuable scientific truth, and cultivated in a spirit 
of enlightened appreciation and criticism, equally 
removed from the blind veneration of the idolater 
and the blind hostility of the iconoclast. It is 
only in this connection that the boundaries of the 
two sciences can be clearly marked out, and those 
portions of psychological matter and phraseology 
whose random introduction has contributed so 
much to deface and obscure the pages of logical 
treatises, can become of inestimable value as part 
and parcel of a cognate and complementary, but 
by no means identical study. And if, in this asso- 
ciation, it becomes necessary to abase considerably 
the once towering ambition of the Art of Arts and 
Science of Sciences, the loss is more than compen- 
sated by the substitution of a humbler indeed, but 
more attainable and more serviceable aim, — the 
knowledge of the distinct provinces to be assigned 
to Thought and Experience respectively, of the 
true value of each within its province, and its 
worse than uselessness beyond ; — the knowledge 
of ourselves and our faculties, of our true intel- 
lectual wealth, the nature of its tenure, and the 
conditions of its lawful increase. By such cultiva- 



288 PROLEGOMENA LOGICA. 

tion alone can we hope to see Logic finally ex- 
hibited in its true character and estimated at its 
true value; neither encumbered with fictitious 
wealth by a spurious utilitarianism, nor unprofit- 
ably buried in the earth of an isolated and barren 
formalism. 



APPENDIX. 



Note A, p. 80. 

It is much to be regretted that Dr. Whewell, who has 
made good use of Kantian principles in many parts of his 
" Philosophy of the Inductive Sciences/' has not more 
accurately observed Kant's distinction between the neces- 
sary laws under which all men think, and the contingent 
laws under which certain men think of certain things. 
His neglect of this distinction has given a seeming ad- 
vantage to the empirical arguments of his antagonist, 
Mr. Mill, who is thus enabled apparently to decide the 
question at issue by what is in reality no more than an 
argumentum ad hominem. Thus Dr. Whewell says of 
certain discoveries of physical laws ; " So complete has 
been the victory of truth in most of these instances, that 
at present we can hardly imagine the struggle to have 
been necessary. The very essence of these triumphs is 
that they lead us to regard the views we reject as not only 
false, but inconceivable." In this relation, it is obvious 
that the inconceivability is, with reference to the human 
mind, merely contingent, and relative to the particular 
studies of particular men. Before the days of Copernicus, 
men could not conceive the apparent motion of the sun 
on the heliocentric hypothesis : the progress of science 
has reversed the difficulty ; but the progress of science 

u 



290 APPENDIX. 

itself is contingent on the will of certain men to apply 
themselves to it. By thus endeavouring to exalt inductive 
laws of matter into a priori laws of mind, Dr. Whewell 
has unintentionally contributed to give an undue plausi- 
bility to the opposite theory, which reduces all laws of 
mind into the mere associations of this or that material 
experience. 

But on psychological grounds it would seem as if the 
point of separation between a priori principles and empirical 
generalizations ought not to be very difficult of deter- 
mination. The difference is not one of degree but of 
kind; and the separation between the two classes of truths 
is such that no conceivable progress of science can ever 
convert the one into the other. That which is incon- 
ceivable, not accidentally from the peculiar circumstances 
of certain men, but universally to all, must be so in con- 
sequence of an original law of the human mind : that which 
is universally true within the field of experience indicates 
an original law of the material world. No transformation 
of one into the other is possible, unless the progress of 
science can change mind to matter or matter to mind. 
It is therefore incumbent on the philosopher who would 
extend mathematical certainty to the domain of physical 
science, to confirm in every instance his theory by a 
psychological deduction of his principles, as Kant has 
done in the instances of Space and Time. 

Dr. Whewell lays much stress on clearness and distinct- 
ness of conceptions as the basis of the axiomatic truths of 
physical science. But the clearness or distinctness of any 
conception can only enable us more accurately to unfold 
the virtual contents of the concept itself: it cannot 
enable us to add a priori any" new attribute. In other 
words, the increased clearness and distinctness of a con- 
ception may enable us to multiply to any extent our 



APPENDIX. 291 

analytical judgments, but cannot add a single synthetical 
one. Without something more than this, the philosopher 
has failed to meet the touchstone of the Kantian question. 
How are synthetical judgments a priori possible ? 

The spirit of Dr. Whe well's Philosophy of the In- 
ductive Sciences is beyond all praise. In these days of 
Positivism and Empiricism, it is refreshing to find a writer 
of such vast attainments in the details of physical science, 
comprising them under such truly philosophical principles. 
But it is to be regretted that the accuracy of his theory 
has been in so many instances vitiated by a stumble on 
the threshold of the Critical Philosophy. The distinction 
laid down by Kant between the synthetical or properly 
geometrical, and the analytical or general axioms, seems 
to have been altogether overlooked. Thus, almost at the 
outset of the Philosophy of the Inductive Sciences, the 
analytical judgment, " if equals are added to equals, the 
wholes are equal," is given as a condition of the intuition 
of magnitudes 3 : and the same oversight runs through the 
Essay on Mathematical Reasoning, in which he speaks of 
" self-evident principles, not derived in any immediate 
manner from experiment, but involved in the very nature 
of the conceptions which we must possess, in order to reason 
upon such subjects at all." The very nature of the con- 
ceptions, however clearly apprehended, can give rise only 
to analytical judgments. 

And such, I think, may be shewn to be the character 
of all the mechanical axioms derived from the idea of 
Force. Of force, apart from the conscious exertion of will, 
we have no positive conception per se: we know it only by 
its effects. Of equal forces we have no positive conception 
beyond that of the production of equal effects. To assert, 
therefore, that equal forces will balance each other at the 
a Book ii. ch. ix. 

u 2 



292 APPENDIX. 

two extremities of a lever, is to assert no more than that 
effects universally equal will be equal in any particular 
case b . 

But to establish Mechanics as an a priori science upon 
the idea of force, it will be necessary to commence with 
some axioms at least of a synthetical character, analogous 
to the geometrical principles, " two straight lines cannot 
enclose a space," or, " if a straight line meets two straight 
lines, so as to make the two interior angles on the same 
side together less than two right angles, the two straight 
lines will meet if produced." 

As a matter of fact, I do not think that Dr. Whewell 
has hitherto succeeded in establishing in the science of 

b We must distinguish between the general theoretical statement of this 
axiom, and its practical application to any given object. In Geometry, 
the axiom, " if equals are added to equals the wholes are equal," is a mere 
analytical judgment derived from the principle of Identity; but to ascertain 
whether two given magnitudes are equal, is a question of experiment or 
observation. So in Mechanics, the axiom, that bodies acting with equal 
forces to turn a lever in opposite directions will retain it in equilibrium, is 
analytical ; and as thus stated, it is unnecessary to add, either that the 
directions of both forces must be perpendicular, or the arms of the lever 
equal. But in any special application of the axiom, there arises at once 
the question, how can we ascertain that any two given forces are equal as 
forces acting upon the lever? If the force, for example, be gravity, and two 
equal weights be suspended, one perpendicularly, the other obliquely, the 
whole weight of the latter does not act to turn the lever in opposition to 
the former ; and the hypothesis of the axiom is violated ; the forces not 
being in that relation equal. Or if both are suspended perpendicularly, 
but at unequal distances from the fulcrum; the moments, or forces in 
relation to the lever, are not equal. The axiom as stated by Dr. Whewell, 
"If two equal forces act perpendicularly at the extremities of equal arms of 
a straight line/' has the appearance of a synthetical judgment, by compre- 
hending under one formula the mere analysis of the notion of equal forces 
and the empirical determination of equality in any particular instance. If 
by equal forces is meant forces equal in effect on the lever, the axiom, as 
stated by Dr. Whewell, is tautological : if the meaning is, forces equal in 
their effects in some other situation, the axiom is empirical only, and not 
even universally true. But, except by its effect in some situation or other, 
what test have we of the magnitude of a force ? 



APPENDIX. 293 

Mechanics a system of a priori synthetical truths derived 
from the idea of force, as distinct from those which are 
mere applications of the mathematical intuitions of time 
or space. But as regards mere hypothetical mechanics, 
such a system is not inconceivable. A more exact psycho- 
logical analysis of the intuitive faculties may possibly 
establish the existence of other subjective conditions of 
intuitions besides those of space and time, and con- 
sequently of other synthetical judgments a priori besides 
those of Geometry and Arithmetic. But when the same 
theory comes to be applied, not to hypothetical rigid bodies 
without weight, but to the actual phenomena of natural 
agents, as in the " Demonstration that all matter is heavy," 
and, verbally at least, in speaking of the inconceivability of 
the pre-Copernican astronomy, we see at once that the 
boundary is overleaped, which separates the necessary 
laws of thought from the generalized phenomena of 
matter. This absolute boundary is sufficiently marked. 
No matter of fact can, in any possible state of human know- 
ledge, be a matter of demonstration. Nay, even supposing 
such a demonstration possible, it would not add one tittle 
to the evidence of the fact, as such, in the eyes of any one 
but an Egoist. By him, it would be accepted as an 
additional proof that what are commonly considered as 
phenomena of the non-ego, are really only modifications of 
the percipient mind, and governed solely by mental laws. 
But to the Realist it would at most only suggest the pos- 
sibility of a pre-established harmony between the laws of 
mind and matter, — a suggestion which would require, in 
every special case, to be verified by the empirical examin- 
ation of the latter. Mental laws, which alone determine con- 
ceivability, are primarily operative only on mental objects, 
and are applicable to external things only on the hypo- 
thesis of their conformity. This hypothesis can only be 



294 APPENDIX. 

verified empirically. That every triangle, for example, 
has its angles equal to two right angles, is strictly true 
only of the perfect triangle as contemplated by the mind. 
That this bit of paper lying before me has its angles 
equal to two right angles, is only true on the supposition 
of its being a perfect triangle ; and the truth of this supposi- 
tion, in any possible state of perfection of human senses 
and instruments, can only be determined empirically. It 
remains always conceivable that there may be an error in 
the measurement, and that the paper may not have exactly 
two right angles. The probability of such an error may 
be diminished to any degree, according to the perfection 
of our means of measurement; but no approximation of 
this kind can ever become absolute certainty. 

It is not without some hesitation that I have ventured 
thus far to criticise a work, which I believe to be, in 
its whole spirit and conception, by far the most valuable 
contribution of modern times to the philosophy of 
the physical sciences. To those who would survey this 
branch of knowledge in a sound philosophical spirit, alike 
removed from the idealism of Schelling, and from the 
positivism of Comte, the writings of Dr. Whewell are 
especially valuable. To those who believe, with the 
present writer, that the future hopes of speculative phi- 
losophy rest on the possibility of a union of the critical 
principles of Kant with the sober practical spirit which is 
characteristic of English thinkers, the writings of the same 
author afford one of the most cheering assurances that the 
spirit of philosophy, under all its discouragements, is not 
yet extinct in this country. With this declaration, the 
spirit that has dictated the preceding criticism will not, 
I trust, be misunderstood. 



APPENDIX. 295 



Note B, p. 135. 

That Berkeley was fully aware of the inconsequence of 
the conclusions which Hume afterwards attempted to 
draw from his principles, is manifest from the third 
Dialogue between Hylas and Philonous, in which he meets 
by anticipation the argument of the sceptic c , by maintain- 
ing that we are directly conscious of our own being. He 
is wrong, indeed, in calling this consciousness Reflection ; 
this term being properly applicable only to attention 
directed to our internal phenomena ; — an attention which 
does not make known, but presupposes, the attending 
self. But when he asserts, " I know or am conscious of 
my own being ; and that I myself am not my ideas, but 
somewhat else, a thinking, active principle, that perceives, 
knows, wills, and operates about ideas ;" he states the 
true ground on which we may refute the sceptical con- 
clusions of Hume. Indeed, this part of the Dialogue wants 
little more than a more complete exposition of the nature 
of the will, to anticipate in principle the position after- 
wards taken against the great sceptic by Maine de Biran. 

The weak side of Berkeley's Idealism is not to be found 
in its relation to Hume, but in its relation to Fichte. 
The object proposed by Berkeley was to get rid of the 
contradictions and difficulties contained in the notion of 
matter as existing distinct from mind, and thus to leave 
the existence of minds, divine and human, beyond question. 
For this purpose, he gave to mind the office which philo- 
sophers had hitherto assigned to matter, — the support of 
accidents. All qualities exist in a mind. If therefore 
they continue to exist when we do not perceive them, 

c This part of Berkeley's Dialogue is meant as an answer to Locke, 
Essay, B. II, ch. 23. §. 5. but the same reasoning is also valid against 
Hume- 



296 APPENDIX. 

(and that they do so is the irresistible conviction of all 
men,) they must be perceived by some other mind. Hence 
the continuous duration of things implies the existence of 
a constantly percipient mind, that is, of God d . This 
theory supposes the idea to be something distinct from 
the percipient mind. If then the things which exist as 
perceived in my mind are perceived at the same time by 
another mind, either my ideas are numerically identical 
with his, or there are as many distinct things as there are 
minds to contemplate them. Hence arises the question, 
Are the objects constantly perceived by the Divine Mind 
numerically one with those at any time perceived by me ? 
If so, our ideas are the ideas of the Deity, and we are 
reduced at once to the Vision in God of Malebranche, 
which Berkeley professes to reject. If, on the other hand, 
the human ideas are numerically distinct from the divine, 
the hypothesis of Berkeley becomes identified with that 
form of Platonism which regards the ideal types of all 
things as existing in the mind of the Deity. Thus pressed, 
the next step for Idealism to take is to abolish the distinct 
idea, and make the object perceived a modification of the 
percipient mind, having no existence out of the personal 
consciousness. Thus the Idealism of Berkeley gives way 
to the Idealism of Fichte ; and the latter furnishes no 
security whatever for Theism. 

These consequences can only be avoided by abandoning 
the Idealistic theory, and substituting a Natural Realism, 
Dualism though it be. Admit, with Berkeley, that the 
real things are those very things which I see and feel and 
perceive by my senses ; but deny his other main position, 
that the mind perceives only its own ideas. The difficulty 
to which Berkeley's theory is subject, concerning the 

d Principles of Human Knowledge, §. xc. Second Dialogue between Hylas 
and Philonous, sub init. 



APPENDIX. 297 

numerical identity of objects perceived, is thus obviated ; 
for, on the hypothesis of Natural Realism, all perception 
is a modification of touch, and no two persons perceive 
numerically the same thing. Thus, if two men are looking 
at the sun, the immediate object perceived by each is the 
rays of light in contact with his own organ of sight e : the 
distant object in the heavens is not perceived, but inferred. 
It is thus as impossible for two persons to see the same 
object with their eyes, as to touch the same spot with their 
fingers. On this theory, we may get rid of the meta- 
physical distinction between phenomena and noumena, or 
between representations and things in themselves. The 
immediate object of perception is the thing; and the 
representation is not opposed to the unperceived thing in 
itself, but to the presentation, or thing as given in 
immediate relation to the conscious subject. 

Another weak point of Berkeley's philosophy is his 
theory of the nature of Belief. He considers that real 
things differ from chimeras, in being more vivid and clear, 
and not dependent on the will. This accords with Hume's 
definition of Belief, "A lively idea, related to or associated 
with a present impression." But the will is completely 
inactive in a dream ; and phantasms may be as lively and 
vivid when excited by a fiction as by a true relation. The 
truth is, that Belief cannot be defined, being presupposed 
in all consciousness. Every act of consciousness is a judg- 
ment, and therefore a belief in the presence of its object : 
the question of reality or unreality depends upon where 
and how we judge it to be present. If an object present 
to the imagination is declared to be present to the sense, 
the judgment is false : but the object is unreal, only if by 
real we mean sensible. The truth then is, that all pre- 
sentations are real relatively to their proper intuition, and 
« See Hamilton on Reid, p. 160, 299, 304. 



298 APPENDIX. 

unreal relatively to any other. And, on Berkeley's hypo- 
thesis, we can carry the distinction no further. But if 
we say, with the Natural Realist, that in perception we 
are immediately conscious of the non-ego, the objects of 
sense are real, as having an existence independently of the 
act of perception ; while the phantasms of the imagination 
may be called unreal, as existing only as modifications of 
the ego. 

Note C, p. 152. 

The following is Mr. Mill's argument for the subjection 
of the human will to the law of physical causation. " To 
the universality which mankind are agreed in ascribing to 
the Law of Causation, there is one claim of exception, 
one disputed case, that of the Human Will ; the deter- 
minations of which a large class of metaphysicians are not 
willing to regard as following the causes called motives, 
according to as strict laws as those which they suppose 
to exist in the world of mere matter. This controverted 
point will undergo a special examination when we come 
to treat particularly of the Logic of the Moral Sciences. 
In the mean time I may remark that these metaphy- 
sicians, who, it must be observed, ground the main part 
of their objection upon the supposed repugnance of the 
doctrine in question to our consciousness, seem to me to 
mistake the fact which consciousness testifies against. 
What is really in contradiction to consciousness, they 
would, T think, on strict self-examination, find to be, the 
application to human actions and volitions of the ideas 
involved in the common use of the term Necessity ; which 
I agree with them in thinking highly objectionable. But 
if they would consider that by saying that a man's actions 
necessarily follow from his character, all that is really 



APPENDIX. 299 

meant (for no more is meant in any case whatever of 
causation) is that he invariably does act in conformity to 
his character, and that any one who thoroughly knew his 
character could certainly predict how he would act in any 
supposable case ; they probably would not find this doc- 
trine either contrary to their experience or revolting to 
their feelings. And no more than this is contended for by 
any one but an Asiatic fatalist f ." 

And no more than this, we might add, is needed to 
construct a system of fatalism as rigid as any Asiatic can 
desire. But we must proceed to Mr. Mill's further 
remarks in the Logic of the Moral Sciences. In this 
latter portion of his work, the author has done little 
more than repeat his belief, that the law of causality 
applies in the same strict sense to human actions as to 
other phenomena, involving in both cases, not constraint, 
but " invariable, certain, and unconditional sequence ;" 
so that, " given the motives which are present to an 
individual's mind, and given likewise the character and 
disposition of the individual, the manner in which he will 
act may be unerringly inferred : that if we knew the 
person thoroughly, and knew all the inducements which 
are acting upon him, we could foretell his conduct with 
as much certainty as we can predict any physical event." 
He adds a distinction intended to rescue his theory from 
the charge of fatalism, as usually implied in the term 
Necessity. " That word, in its other acceptations, involves 
much more than mere uniformity of sequence ; it implies 
irresistibleness. Applied to the will, it only means that 
the given cause will be followed by the effect, subject to 
all possibilities of counteraction by other causes : but in 
common use it stands for the operation of those causes 
exclusively, which are supposed too powerful to be coun- 
f Mill's Logic, vol. i. p. 419. 



300 APPENDIX. 

teracted at all." " The causes therefore," he continues, 
" on which action depends, are never uncontrollable ; 
and any given effect is only necessary provided that the 
causes tending to produce it are not controlled. That 
whatever happens could not have happened otherwise, 
unless something had taken place which was capable of 
preventing it, no one surely needs hesitate to admits." 

That there is some fundamental weakness in the above 
theory, appears almost on the surface, from the fact that 
so acute a thinker as Mr. Mill can imagine that he has 
saved the principle of causality from the charge of 
fatalism by this concluding paragraph. That whatever 
happens could not have happened otherwise, unless some- 
thing had taken place capable of preventing it, is indeed 
in one sense a perfectly harmless position, but also a 
perfectly unproductive one. It is the mere truism of the 
Nursery Rhyme : 

" There was an old woman lived under a hill, 
" And if she's not gone, she lives there still." 

Examine it closer, and the question at once arises, whence 
is this counteracting cause to come ? If from myself, 
from a self-determined act of free will, this concedes the 
whole question at issue. If from an act of will deter- 
mined by preexisting causes, or altogether from without, 
I am still in the iron grasp of Necessity. If the pre- 
venting circumstance, come whence it may, comes as the 
certain sequence of antecedent phenomena, I am still the 
slave of circumstances : if otherwise, the whole resemblance 
between moral and physical causation vanishes. 

But let us go up to the fundamental principle of the 
theory itself. The conduct of a man, we are told, is the 
invariable consequent of motives present to his mind ; so 

g Mill's Logic, book vi. chap. 2. 



APPENDIX. 301 

that, given the motives and the man's character, we could 
certainly predict the action. Character , it must be ob- 
served, is not here to be understood in Aristotle's sense, 
as a disposition caused by a series of voluntary acts: it 
must be something coeval with the first act of so-called 
volition. At the earliest period at which I am capable of 
acting, I possess a character of some sort ; and that cha- 
racter, together with the motives presented, determines 
certainly how I shall act. 

The plausibility of the theory arises from an ambiguity 
in the term motive. In knowing the phenomena present 
to a man's mind at the moment of any act of volition, is it 
included that we are to know their relation to his will? 
If so, the supposed prediction is a mere begging of the 
question : when I know how he will be inclined to act, 
I know how he will act. If not, the advocate of the 
doctrine must succumb to the sophism of the Asinus 
Buridani, and concede that the unfortunate animal, be- 
tween two bundles of hay exactly alike, must starve. 
The solution of this sophism, supposing, of course, that 
the ass in that instance represents a voluntary, and not 
merely a spontaneous agent, is likewise the solution of 
Mr. Mill's argument. What is meant by two bundles of 
hay exactly alike ? They must be indistinguishable by 
sight, smell, touch, and so forth. But are objects exactly 
similar as regards the senses, therefore exactly similar as 
regards the will ? A lump of salt and a lump of sugar 
may be similar to the eye : are they therefore similar to 
the palate ? If taste is not dependent upon another sense, 
why may not will be independent of all the senses? If, 
on the other hand, the two bundles of hay are to be 
exactly similar, as motives in relation to the will, the argu- 
ment amounts to the mere truism, that if the ass does not 
choose one he will choose neither. 



302 APPENDIX. 

Exactly the same fallacy runs through Mr. Mill's theory 
of the causality of actions. The so-called motives are 
either a set of phenomena viewed in their relation to the 
will, or viewed out of that relation. If the former, the 
argument has ]ong ago been refuted by Reid h . The 
strongest motive prevails ; but I only know the strength 
of motives in relation to the will by the test of ultimate 
prevalence ; so that this means no more than that the 
prevailing motive prevails. I have no measure of strength 
but its effects. I only know certain things to be motives 
at all, by the fact of their ultimate prevalence. If, on the 
other hand, the phenomena are considered out of their 
relation to the will, my consciousness testifies at once 
that my actions are not subject to the same invariable 
sequence as physical changes. I know, that is, whenever 
I lift my arm to my head, that it is at that moment in my 
power not to lift it ; and that, the antecedent circum- 
stances being precisely the same, I may decide not to do 
so at any future time. But, says Mr. Mill, this decision 
of the will is itself a new antecedent \ Certainly, a new 
antecedent to the act ; but with what propriety can it be 
called a new antecedent to itself? The question is not 
whether the act of motion follows certainly upon that of 
volition, but whether the act of volition follows certainly 
upon antecedent circumstances. The former sequence 
depends on purely physical laws ; and the preventing 
causes, such as a stroke of paralysis, are purely physical 
also. But if the latter sequence is invariable also, we 
admit, not one new phenomenon, but millions ; since an 



h Active Powers, Essay iv. ch. 4. p. 610. ed. Hamilton. 

» Mr. Mill says, " the wish is a new antecedent." If this term is meant 
to be synonymous with will, it would he an improvement in language to 
change it: if it is meant to be synonymous with desire, the confusion of 
desire with will vitiates his whole argument. 



APPENDIX. 303 

opposite determination of the will can only come in with 
its determinant, and the determinant of that determinant, 
and so on ad infinitum. For to suppose that two opposite 
volitions can follow from the same determinant is incom- 
patible with the whole hypothesis of causality. If, on the 
other hand, the sequence of volition from given ante- 
cedents is variable, what becomes of the power of pre- 
dicting a man's actions ? The contingency of a single 
link affects all the subsequent portion of the chain. 

In reply then to the question, Are our volitions, like 
other events, the result of causes ? Certainly not, in the 
only intelligible senses of the term. I have only two 
positive notions of causation : one, the exertion of power 
by an intelligent being ; the other, the uniform sequence 
of phenomenon B from A. (A may here stand for a single 
phenomenon or a group; for that antecedent or sum of 
antecedents which constitutes the Sufficient Reason.) 
The former hypothesis is Fatalism. If my will results 
from the coercion of some other intelligence, I am the 
slave of Destiny. The latter hypothesis is Determinism, 
a necessity no less rigid than fatalism, besides being at 
variance with the whole testimony of consciousness and 
with the experience of every day. Besides these two, 
there is no alternative, but to admit in the fullest sense 
the freedom of the will, by denying the applicability of 
the principle of causality to human actions. 

" This objection, if not removed," says Mr. Mill, "would 
be fatal to the attempt to treat human conduct as a subject 
of science." Be it so. It is better to accept the con- 
clusion than to admit the premise. But it is fatal only 
according to Mr. Mill's view of science. Ethology, as he 
conceives it, in relation to individuals, as the science of 
characters as they must be according to laws of physical 
and mental causation, I do believe to be, in its idea and 



304 APPENDIX. 

pretensions, chimerical: but Ethics, as the science of such 
characters as they ought to be according to the laws of 
moral obligation, remains undisturbed, or rather, more 
securely established. It seems to be forgotten by writers 
of this school, that these two systems are absolutely 
exclusive of each other; that physical causation and moral 
obligation cannot in perfection exist side by side ; and 
that where they do coexist, each must be in the inverse 
ratio of the other. In proportion as we extend the 
domain of Necessity, we must diminish that of Duty; 
and Necessity, notwithstanding all that Mr. Mill has 
advanced, I still believe to be the inevitable result of 
subjecting moral acts to the laws of physical causation. 
But Ethology, in relation to classes of men, as affected by 
national, professional, educational, physiological, or even 
moral circumstances, may notwithstanding attain to a vast 
amount of important practical principles and rules ; though 
still subject to the influence of individual contingency. 
The actuary of an insurance company, if he were to 
predict the duration of life of any one individual on the 
books of his office, would in all probability guess wrong; — 
as a matter of fact, it is true, mainly from his ignorance of 
physical circumstances ; but as a matter of theory also, if 
we allow that the individual in question may falsify the 
prediction by a voluntary act of suicide. But if the same 
experiment is tried on a sufficiently large scale, opposite 
errors will counteract each other, and the general ap- 
proximate result attains almost to a moral certainty. 
The general results of Ethology, as applied to classes, are 
dependent in a great degree on similar circumstances, and 
may attain to the same or a higher amount of practical 
utility. 

In the course of the above remarks, I have purposely 
avoided touching on a subject alluded to by Mr. Mill, the 



appendix. ;305 

compatibility of man's free-will with God's foreknowledge. 
This question is insoluble, because we have nothing but 
negative notions to apply to it. To enable us to determine 
the exact manner in which an Infinite Intelligence con- 
templates succession in time, it would be necessary that 
our intelligence should be infinite also. In this, as in 
all other revelations of God's relation to man, we must 
be content to believe without aspiring to comprehend. 
The fact of God's foreknowledge is all that is revealed to 
us : the manner He has left in darkness, and we cannot 
enlighten it. But we are not justified in rejecting what 
we can comprehend because we do not understand :+ ~ 
possible relation to what we cannot. That no conceivable 
amount of information could enable a being of human 
constitution to predict with certainty the acts of another, 
is established by the same evidence of consciousness by 
which we know that there is a human constitution at all. 
How far the same conclusion can be transferred to other 
orders of finite beings, still less to an Infinite Intelligence, 
we have no data for determining. 



Note*D,p. 153. 

An eminent Philosopher of the present day, from whose 
slightest assertion it is impossible to dissent without much 
diffidence, has maintained that the schemes of Liberty and 
Necessity are both equally inconceivable, though for the 
fact of Liberty we have, immediately or mediately, the 
evidence of consciousness k . In the cursory observations 
to which Sir William Hamilton is confined by the limits 
of a foot note, it would not be fair to expect a complete 
discussion of the question; but, pace tanti viri, I can 
hardly think his conclusion made out by what he has there 
k Sir W. Hamilton, Etid's Works, p. 599, 602. 
X 



306 APPENDIX. 

advanced. His doctrine appears substantially to correspond 
with that of Kant, who, in his third Contradiction of 
Transcendental Ideas, has arranged in parallel columns the 
opposite arguments in behalf of Liberty and Necessity, 
with the view of shewing that each is irresistible in its attack 
upon the other. But Kant's reasoning is essentially 
vitiated by the fundamental error in his psychology to 
which I have before alluded, the denial of an immediate 
consciousness of self. The conclusion of Sir W. Hamilton, 
that for the fact of liberty we have the testimony of con- 
sciousness, is substantially the same to which M. Cousin 
arrives in his criticism of Kant's theory; and the fact 
itself, as he justly observes, is one which no reasoning need 
or indeed can establish. Any weakness therefore which 
the necessitarian may detect in the arguments in favour of 
liberty is of no consequence ; for the fact is equally certain 
if no argument can be advanced in its favour. But, on the 
other hand, in conjunction with the assertion of the fact, 
it is necessary to shew the error of the arguments for 
necessity, if we would not acquiesce in the melancholy 
conclusion that the deductions of reasoning and the facts of 
conscience are contradictory of each other. But if this can 
be done, it does not appear why the scheme of liberty 
should be called inconceivable : it is inconceivable only by 
reason of the apparent demonstration of the opposite system. 
If indeed we define Liberty, with Reid, as a power over 
the determinations of our own will, and suppose that 
determination to be itself a result of a volition, the deier- 
minist reasoning is unavoidable : we must will to determine, 
and will to will to determine ; and so on ad infinitum. 
Nor was it possible for Reid to evade this attack by a 
more accurate view of determination, so long as he held, 
in conjunction with his erroneous theory of consciousness, 
the doctrine of the universal authority of the principle of 



APPENDIX. 



307 



causality. If I am conscious only of phenomena of mind, 
my first consciousness relative to volition is simply that of 
a phenomenal mode of existence, to which by the principle 
of causality I am bound to suppose a determining phe- 
nomenon, and to that again another, and so on for ever. 
But if my primary consciousness is not merely of the phe- 
nomenon of volition, but of myself as producing it, I am not 
compelled to go back to any prior cause whatever. I need 
not suppose a prior intelligent cause ; for my only positive 
notion of such a cause is myself determining, which does 
not imply myself determined. I need not suppose a prior 
phenomenal cause; for such cause is always invariable, and 
the mere chronological antecedents of my volition have no 
such character. The whole point at issue thus turns on 
the following question, Can the fact of consciousness 
expressed in the judgment / will, be analysed into a rela- 
tion of phenomena subject to the law of causality? Is 
the principle which we invariably apply to the sequence 
of one phenomenon on another also applicable to the 
relation of any phenomenon to the one given cause, myself? 
Sir William Hamilton lays much stress on the impos- 
sibility of conceiving an absolute commencement. If by 
this is meant that I cannot conceive myself standing at 
the beginning of all time, out of all relation to any ante- 
cedent series of phenomena, it is undeniably true. But 
is such a conception needed to render the scheme of 
Liberty comprehensible ? Is it not sufficient for me to 
know that none of the chronological antecedents stand to 
my volition in the particular relation of a determining 
cause ? And this is the case, if it is neither given as an 
active power coercing nor as a passive phenomenon in- 
variably preceding. To say that some antecedent or other 
must go before my will, is only to say that I do not stand 
at the beginning of all time : but does this imply some 

x2 



308 APPENDIX. 

one antecedent which is invariably followed by volition ? 
If, on the presence of the antecedent or group of ante- 
cedents, A, my volition sometimes takes place one way 
and sometimes another, it is not determined in the same 
manner as physical phenomena. If there is not always 
present some conscious being, exerting his power over 
my will, it is not determined in the same manner as it 
determines its own volitions. But excepting these two 
senses, what is meant by determining cause ? 

Is there then extant any definition of will which does 
not imply another will preceding ? Perhaps not; but the 
fault lies only in the authors of the definitions. To refute 
a given definition does not prove the non-existence of 
the thing defined. If liberty itself is a simple fact of con- 
sciousness, the error lies in -the attempt to define it at all. 
The definition will necessarily involve a circle, and upon 
that circle, and not on the fact, the antagonist reasons. 
But then if the definition and the fact of consciousness are 
at issue, the former must give way, not the latter. Now 
consciousness tells me, not that my will wills, but that 
I will. Is it necessary to the conceivability of this fact, 
that I should be able to analyse it into two constituent 
elements, — to place an abstract Ion one side, and an abstract 
will on the other; thus literally fulfilling the satirical 
direction for the turbulent puritan's burial, by laying John 
apart from Lilburn and Lilburn from John? Will any 
other state or act of mind bear a similar analysis ? Can 
I in any case separate the state from the mind and the 
mind from the state; or give any definition which does 
not virtually repeat itself? But is it correct, on that 
account, to call states which I experience every day in 
consciousness inconceivable ? 

In conclusion, I trust it will be borne in mind that the 
above remarks, so far as they relate to Sir W. Hamilton, 



APPENDIX. 309 

are only provisional, and proceed on the supposition that 
his doctrine is in the main identical with Kant's. In 
the whole range of philosophers of the present or any 
other period, it would be hard to name one, whose mere 
ipse dixit, from his almost universal learning and sin- 
gular freedom from the prejudices of any sect, is entitled 
to so much respect as Sir William Hamilton's. But if 
I understand rightly the force of his objection, I can only 
reply, that, so far as I can attach any meaning to the 
terms cause and effect, I have no difficulty in conceiving an 
act which is a cause without being an effect ; but that by 
the absence of a cause, I do not mean the absence of all 
relation to a chronological antecedent. Thus interpreted, 
I believe the scheme of liberty is inconceivable only if 
the determinist argument is Unanswerable ; and its answer 
is what I have attempted in this and the preceding note. 
If the attempt to establish a contradictory conclusion fails, 
liberty, though not definable, is surely as conceivable as 
any other simple datum of consciousness. 



Note E, p. 155. 

That our earliest notion of Causality arises from the 
fact given in the determination of our own volitions, is 
suggested by Locke and established beyond all question 
by Maine de Biran. But then arises the question : by 
what process do we transcend our personal consciousness, 
and acknowledge, in relation to the changes of the sensible 
world, the operation of causes other than ourselves ? This 
process is called by De Biran and by Royer-Collard a 
Natural Induction, a term severely criticised by M. 
Cousin. Were the process really inductive, he argues, 
we must believe every cause in nature to be like our- 



310 APPENDIX. 

selves, voluntary, conscious, and free ; and even then, the 
belief in question might perhaps be regarded as universally 
true within the limits of experience, but could never rise to 
the character of a necessary truth. For a more satisfactory 
explanation, M. Cousin has recourse to the principle of 
causality, which he regards as a necessary law of the 
reason, by virtue of which it disengages, in the fact of 
consciousness, the necessary element of causal relation 
from the contingent element of my personal production 
of this or that particular movement. This necessity, 
which compels the reason to suppose a cause whenever 
the senses or the consciousness present a phenomenon, is 
the Principle of Causality 1 . 

It is obvious to ask, wdiat do we gain by the principle 
of causality thus supposed ? Does it explain in any degree 
the nature of that power which we are supposed to at- 
tribute to inanimate objects ? Does it explain how we 
divest our original notion of the attribute of personality, 
and what is left when we have done so ? Does it furnish 
the slightest hint or help for investigating the true cha- 
racter of efficient causes ? By no means. The principle 
itself is a mere statement of the fact, that we do in- 
variably suppose a cause of physical changes, and that 
we cannot but do so. It ofTers no psychological ex- 
planation of the fact : it merely gives it the name of a 
principle of reason. It does not give us any positive 
notion of the cause in question : this remains, we know 
not what, — a something different from our own causality, 
and, as such, supposable perhaps, but inconceivable. It 
does not tell us how we can attain to a more positive 
knowledge. Not by the senses ; for these present to us 
only successive phenomena. Not by the internal con- 
sciousness ; for this informs us only of personal causation. 

1 Cours de Philosophic, Leyon 19, 



APPENDIX. 311 

Not by the reason; for this only tells us in general terms 
that there is a cause, but furnishes no means of observing 
and distinguishing its character and varieties. The cause 
of physical changes still remains, like the subject of 
physical attributes, a negative idea, aje ne sais quoi. 

Nor does M. Cousin's theory, any more than that of 
De Biran, explain how we get rid of the personal element 
with which all intuitive causality is involved. It only 
says that we do so, and that we must do so. The term 
Induction, employed by De Biran and Roy er- Collar d, is 
indeed objectionable, whether it be taken in the Aristo- 
telian or in the Baconian sense. The former is objection- 
able; inasmuch as our personal acts are not supposed to 
constitute, or even adequately to represent, the whole body 
of causal relations. The latter is objectionable ; for the 
same acts cannnot be selected instances shewing diverse 
operations of a law, but must, from the nature of the case, 
be all of one kind. But this objection affects only the 
language, and not the basis of the theory: indeed, the two 
philosophers in question have expressly stated that their 
natural induction must be carefully distinguished from that 
of physics™. But in point of language, the phrase principle 
of reason is equally objectionable; partly as tending to 
check all further psychological investigation into a point 
by no means as yet satisfactorily explained, and partly as 
opening the way to the thousand extravagances of onto- 
logical speculation, by concealing the purely negative 
character of the notion of physical power. On M. de 
Biran's theory, says M. Cousin, anthropomorphism be- 
comes the universal and necessary law of thought 11 . It 
might be replied, that in all cases where the presentation 

m (Euvres de Maine de Biran, vol. iv. p. 393. Jouffroy's Beid, vol. iv. 
p. 383, 439. 

n (Euvres de Maine de Biran, vol. iv. Preface de l'Editeur, p. xxxvi. 



312 APPENDIX, 

is given by internal consciousness only, anthropomorphism 
is in fact the condition and the limit of all positive 
thinking. 

I conceive, therefore, that there is nothing in M. 
Cousin's theory which dispenses with the obligation of 
a further psychological examination of the origin and 
character of the supposed principle of causality, such as I 
have attempted in the text of the present work. Whether 
that explanation itself be right or wrong, must be j udged 
by others ; but, whatever may be its fate in this respect, 
I shall deem its purpose sufficiently answered, if it serves 
to call the attention of philosophers to a point hitherto too 
much neglected in speculation, the important distinction 
between positive and negative intuitions and thoughts. 



Note F, p. 158. 

In the controversy concerning the existence of a Moral 
Sense, the question at issue has suffered considerable mis- 
representation, from the want of an accurate distinction 
between intuitive or presentative consciousness, whose 
object is an individual thing, act, or state of mind, and 
reflective or representative consciousness, whose immediate 
object is a general notion or principle. Stewart, for 
example, in his Life of Adam Smith, observes, " It was 
the opinion of Dr. Cudworth, and also of Dr. Clarke, that 
moral distinctions are perceived by that power of the 
mind which distinguishes truth from falsehood. This 
system it was one great object of Dr. Hutcheson's philo- 
sophy to refute, and in opposition to it, to shew that the 
words right and wrong express certain agreeable and dis • 
agreeable qualities in actions, which it is not the province 
of reason but of feeling to perceive ; and to that power of 



APPENDIX. 313 

perception which renders us susceptible of pleasure or of 
pain from the view of virtue or of vice, he gave the name 
of the Moral Sense." The same philosopher, in his 
Philosophical Essays, endeavours to obviate Hume's de- 
ductions from Hutcheson's theory, by falling back, in 
some degree, upon the views of Cudworth and Clarke, 
and referring the origin of our notions of right and wrong 
to reason instead of sense, " Tastes and colours," said 
Hume, " and all other sensible qualities, lie, not in the 
bodies, but merely in the senses. The case is the same 
with beauty and deformity, virtue and vice." To this 
Stewart replies, " The decisions of the understanding, it 
must be owned, with respect to moral truth, differ from 
those which relate to a mathematical theorem, or to the 
result of a chemical experiment, inasmuch as they are 
always accompanied with some feeling or emotion of the 
heart; but on an accurate analysis of this compounded 
sentiment, it will be found, that it is the intellectual 
judgment which is the groundwork of the feeling, and not 
the feeling of the judgment." 

In a Lecture on Moral Relations, by the late Professor 
Mills, the different opinions concerning our perception of 
Morality are summed up as follows. 

" 1. Some ascribe our apprehension of it, with Hutche- 
son, to a peculiar internal sense, similar in its operations 
to the external senses, and confound moral perception 
with taste : this is, strictly speaking, the theory of a moral 
sense. 

" 2. Others attribute moral perception, not to any 
peculiar sense, but yet to a peculiar faculty of the under- 
standing distinct from its general powers, and they appear 
to identify conscience with the moral faculty. 

" 3. Many deny the existence of a peculiar moral faculty, 
and maintain that moral principles are apprehended by 



314 APPENDIX. 

the same powers of the intellect which perceive other 
kinds of truth. 

" 4. The Utilitarian theory implies that moral relations 
are ascertained and embraced by the operations of the 
discursive faculty onlyC 

The whole controversy may be considerably cleared by 
distinguishing Moral Facts from Moral Principles. Facts 
of all kinds are presented to, and perceived by, different 
faculties of intuition, similar in the manner of their 
operation to the perceptions of sense : and hence, with 
some allowance for metaphor, we may speak of internal 
or external senses r . Is it then asked whether we discern 
morality in individual acts, by the same faculties by which 
we discern other qualities of individual objects presented 
to us ? But of these qualities, some are visible, some 
audible, and so on. Is it meant that an act can literally 
be seen, heard, smelt, felt, or tasted, to be virtuous or 
vicious ? If not, the perception of the moral character of 
acts is a distinct presentation, and, as such, to be referred 
to a distinct faculty; though, being, as will appear, an 
object of internal, not of external perception, it is not, 
like the external senses, connected with a distinct bodily 
organ. 

The question, whether right and wrong are apprehended 
by the same powers of the intellect which perceive other 



q Essays and Lectures by the late Rev. W. Mills, p. 204. 

r This has heen ohserved by Aristotle, whose account of the Practical 
Sense or Intelligence is in this respect more accurate than that of modern 
philosophers. Kal yap toov irp&Tcav opwu Kal t£>v iffx^Tcau vovs ecrrl Kal ov 
Xoyos, Kal 6 fx\v Kara, ras airoSei|ets rcov aKivi]T(av '6poov Kal irp&roov, 6 8' 4v 
rats irpaKTiKals tov io'X"' TOV Ka ^ euSexofievov Kal rrjs erepas irpo- 
t d ere us' apxal yap tov ov eveKa avrar 4k toov /ca0' %KattTa yap to KaQ6\ov. 
Tovtoov odv ex €lv ^" a'to-Q^o-iv, avT-r\ 8' £cttI vovs. This remarkable 
passage may serve as a qualification of Smith's assertion, that the word 
moral sense is of very late formation. 



APPENDIX. 315 

kinds of truth, is only applicable to the general concepts 
or principles, through which morality is represented as an 
object of thought. Truth and Falsehood can be dis- 
tinguished in representative knowledge only ; and all such 
knowledge is most conveniently classified by reference to 
the single faculty of the Understanding. The same power 
of thought may enquire into the ground of various pre- 
sentations : it may investigate, for example, why one 
object is white, why another is harmonious, why a third 
is sweet, why a fourth is beautiful, why a fifth is virtuous ; 
but in all such investigations, the fact of a given object 
possessing a given quality must be presupposed as the 
groundwork of the investigation. The distinction be- 
tween a true and a false theory of morals will be deter- 
mined by the same test as that between truth and false- 
hood in any other inquiry ; — its agreement or not with the 
facts as given in intuition. 

It thus appears, that a power of discerning right and 
wrong in individual acts must be allowed as the present- 
ative basis, without which no system of Moral Philosophy 
is possible. Such a power, thus limited, it is impossible 
for the Utilitarian to explain away by any theory of 
association or education. Education may corrupt and 
pervert our presented ideas, but it cannot originate them: 
it may teach me to regard an act as right which is really 
wrong, or vice versa, but it cannot create the original 
impression of either. To deny, with Locke and Paley, 
the existence of a moral sense, because one man holds to 
be wrong what another holds to be right, is like denying 
the existence of a faculty of sight, because a man with the 
jaundice sees all objects yellow. The existence of the 
faculty is shewn by our approving or disapproving at all : 
it cannot therefore be disproved by the fact of our some- 
times approving or disapproving wrongly. The opposite 



316 APPENDIX. 

error of Hume, in holding that virtue and vice exist in 
the sense only, lies in a confusion of the subjective feeling 
of approbation with the objective quality which gives rise 
to it. The same confusion has taken place with regard to 
the secondary qualities of body. Heat and colour, as 
sensations, exist only in a sentient being ; but that such 
sensations originate from nothing at all in the bodies them- 
selves, is an absurdity long ago exploded, if indeed ever 
seriously maintained. 

This presentation of right and wrong, however, is by 
no means accurately exhibited in the account commonly 
given of moral sense. It is not correct to describe our 
perception of the moral character of actions in general 
as coordinate with or including the judgment of our 
own conduct in particular 8 . Right and wrong are not 
directly presented to me in any other actions than my own. 
If I see a murder committed in a puppet-show, I have all 
the same presented phenomena as if I see a murder com- 
mitted by a man. I do not feel the same moral disappro- 
bation, because I do not attribute to the puppet the 
same internal consciousness of obligation as to the man. 
But this consciousness is not presented except in the case 
of my own acts, and, from these, is transferred represent- 
atively to other men, whose mental constitution I believe 
to be in this respect similar to my own. The intuitive 
faculty is properly limited to the approbation or disappro- 
bation of my personal acts ; and to this personal conscious- 
ness must thus be traced the original notions of Right and 
Wrong, as of Cause, and of Substance, and of all internal 
phenomena. Hence, if the terms Moral Sense and Con- 

s As is done by Bishop Sanderson, in his Prcelectiones de Obligatione 
Conscientice, as well as by Shaftesbury, Hutcheson, and most of the 
advocates of a moral sense, and still more by Smith, in his theory of 
Sympathy. 



APPENDIX. 317 

science be used in the ordinary philosophical distinction, it 
will be more correct to describe Moral Sense as an ex- 
tension of Conscience, than Conscience as a limitation of 
Moral Sense 1 . 



Note G, p. 233. 
The difference between the relations of the several 
Forms of Thought to Psychology and to Logic has not 
hitherto been accurately marked. Psychologically, all 
that is communicated by, not given to, the act of thinking, 
belongs to the form, not to the matter, of the product. 
But these psychological forms do not come within the 
province of Logic, unless some further process of pure or 
formal thinking is affected by them. In its psychological 
relation, modality is clearly one of the forms of judgment. 
The necessary judgment, " A must be B," expresses the 
existence of a law, of some kind or other, by which the 
attributes are inseparably connected : the contingent 
judgment, whose full expression is, "A may or may not 
be B," denies the existence of any law of the kind : while 
the pure judgment, " A is B," states the fact of an existing 
connection, without taking into account the question of 
law at all. The psychological question is this : " Is the 
presence or absence of a law connecting the terms of a 
judgment given to or by the act of judging ? Is it part of 

1 This is exactly the reverse of the theory of Adam Smith, who main- 
tains that our judgments concerning the morality of our own acts is 
entirely derived from that which we pass on others. This theory he carries 
so far as to assert, " Were it possible that a human creature could grow 
up to manhood in some solitary place, without any communication with 
his own species, he could no more think of his own character, of the pro- 
priety or demerit of his own sentiments and conduct, of the beauty or 
deformity of his own mind, than of the beauty or deformity of his own 
face." 



318 APPENDIX. 

the given phenomena, or a manner in which the mind 
regards them ? In other words : Is modality an affection 
of the predicate, or of the copula ? Do I in thought 
decide on the actual connection of A with a given 
necessary-B, or on the necessary connection of A with a 
given B ? In the former case, the modality belongs to 
the matter of the judgment ; in the latter, to the form. 

The true answer to this question is sufficiently plain. 
If sensible experience is incompetent to furnish the 
notion of identity between two phenomena, it is equally 
incompetent to furnish that of necessary or contingent 
identity. These are additional products of the act of 
thought; experience having only presented the pheno- 
mena in a constant or variable juxtaposition. Nay further, 
the hypothesis that modality is given in the predicate of 
a judgment, not thought in the copula, becomes, in ulti- 
mate analysis, destructive of itself. For, if in thought 
we connect A with what is given as necessarily B, this 
implies that B has previously been thought as necessarily 
connected with some subject or other. A necessary-B 
has no intelligible sense, except in relation to some 
previous judgment, " C must be B." The identification 
of A with B then takes place through the medium of C; 
and the supposition that modality can be given as an 
affection of the predicate, implies that it has been pre- 
viously thought as an affection of the copula. This is 
sufficient to establish the psychological position of modality 
as a form of the judgment. But, thus admitted, it is 
indispensable that it should be expressed in the copula, 
and not, as is frequently done, left to be gathered from 
our knowledge of the matter. A judgment of the form 
" A is B," whatever notions may be expressed by the 
terms, can never be thought as other than a pure or 
assertorial judgment. An apodeictical or problematical 



APPENDIX. 3VJ 

judgment requires a different statement of the copular 
relation, " A must be B," or "A may be B." 

On the other hand, the criticism of Sir W. Hamilton, 
though accurately expressed in relation to one process of 
thought only, may be so extended as to be decisive as 
regards the exclusion of modality from Logic. " Necessity, 
Possibility, &c." he says, " are circumstances which do 
not affect the logical copula or the logical inference. 
They do not relate to the connexion of the subject and 
predicate, of the antecedent and consequent, as terms in 
thought, but as realities in existence ; they are meta- 
physical, not logical conditions. The syllogistic inference 
is always necessary ; it is modified by no extraformal 
condition; is equally apodeictic in contingent as in neces- 
sary matter 11 ." 

As regards the syllogistic inference, these remarks are 
strictly accurate, and would be conclusive against any 
modality proposed as a form of reasoning. Were a 
distinction, for example, set up between syllogisms in 
which the conclusion necessarily follows from the pre- 
mises, and syllogisms in which it may be inferred with 
more or less probability, the latter would rightly be 
condemned as extralogical ; the true syllogistic inference 
being always necessary. As regards the copula in judg- 
ments, the criticism cannot be accepted as verbally accurate, 
unless we distinguish the logical copula from the psycho- 
logical. That modality relates to realities in existence, 
is not conclusive ; for quantity and quality, in all syn- 
thetical judgments, do the same in the same degree, and 
yet are rightly classed as forms of thought. But if we 
extend the distinction between formal and material 
thinking, so as to embrace judgment and conception, as 
well as reasoning, it is clear that the copula is always 

" Edinburgh Review, No. 115, p. 216. 



320 APPENDIX. 

necessary in analytical or formal judging, as the inference 
is always necessary in formal reasoning. Material judg- 
ments, however, cannot be entirely excluded from Logic, 
in so far as they furnish data for formal reasoning. They 
are admissible, however, only in relation to this latter 
process ; and hence those forms of judgment only are 
rightly to be regarded as logical, which affect the formal 
inference derivable from them. This is the case with 
quantity and quality, but not with modality : the latter 
affects the conclusion of a syllogism, not as a conclusion, 
in its relation to the premises, but only in itself, as a 
proposition. For this reason, it is logically preferable to 
exclude modality as a form, and to treat it as if it affected 
the predicate only of the judgment. The logical copula 
thus becomes in every instance assertorial only; and if this 
be carefully distinguished from the psychological copula, 
the remarks of Sir W. Hamilton may be regarded as 
applicable to the whole of Logic, and to every process of 
thought. 



THE END. 



BAXTER, PRINTER, OXFORD. 



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